Vulnerability-Lookup

CVE-2026-74630 (GCVE-0-2026-74630)

Vulnerability from cvelistv5 – Published: 2026-08-22 15:32 – Updated: 2026-08-25 05:40

Title

ipv6: prevent in6_dev_get() from resurrecting inet6_dev

Summary

In the Linux kernel, the following vulnerability has been resolved: ipv6: prevent in6_dev_get() from resurrecting inet6_dev in6_dev_get() reads dev->ip6_ptr under RCU and then unconditionally increments its refcount. Device teardown can clear the pointer and drop the last reference between these operations. The increment then resurrects an object whose RCU free has already been queued, so callers can use it after it is freed. Use refcount_inc_not_zero() and return NULL when the object has already reached zero. RCU keeps the memory accessible through the attempted reference acquisition, and a successful increment pins the object for the caller. An independent run on the exact unpatched 6f5156d7a31a (v7.2-rc3) kernel reproduced the invalid reference acquisition as UID 1000: refcount_t: addition on 0; use-after-free. ip6_mc_source+0xef4/0x17e0 It was followed by the corresponding reference underflow in ip6_mc_source(). The supplied trace from the same unpatched revision additionally shows the access after the RCU read-side section ends: BUG: KASAN: slab-use-after-free in mutex_lock+0x76/0xe0 Write of size 8 at addr ffff888015b50240 by task poc/1219 Bug found and triaged by OpenAI Security Research and validated by Trail of Bits.

Severity

7.8 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Assigner

Linux mitre root

References

8 references

URL	Tags
https://git.kernel.org/stable/c/785d908f8d21c8bc7…
https://git.kernel.org/stable/c/aedcfefdb5b7ed7f8…
https://git.kernel.org/stable/c/145812b678de9f3b5…
https://git.kernel.org/stable/c/cc5bd568f9b7683e6…
https://git.kernel.org/stable/c/1c206d461c680c315…
https://git.kernel.org/stable/c/680fbd7942185448e…
https://git.kernel.org/stable/c/14e812ab41df0cac0…
https://git.kernel.org/stable/c/0e243671bc7b8eaf0…

Impacted products

2 products

Vendor	Product	Version	CPE status
Linux	Linux	Affected: 8814c4b533817df825485ff32ce6ac406c3a54d1 , < 785d908f8d21c8bc78b6fb2c2932ab662bf6918a (git) Affected: 8814c4b533817df825485ff32ce6ac406c3a54d1 , < aedcfefdb5b7ed7f8a6196a3e68a25bdbe51d2f8 (git) Affected: 8814c4b533817df825485ff32ce6ac406c3a54d1 , < 145812b678de9f3b59780173be3c0d22ed60dd93 (git) Affected: 8814c4b533817df825485ff32ce6ac406c3a54d1 , < cc5bd568f9b7683e60841b6fd02c10d64535bd6e (git) Affected: 8814c4b533817df825485ff32ce6ac406c3a54d1 , < 1c206d461c680c3151daa3c89fc26eaf5bf98a7f (git) Affected: 8814c4b533817df825485ff32ce6ac406c3a54d1 , < 680fbd7942185448eadb990a3d10a53eb946b702 (git) Affected: 8814c4b533817df825485ff32ce6ac406c3a54d1 , < 14e812ab41df0cac033479da835ec9a5de633404 (git) Affected: 8814c4b533817df825485ff32ce6ac406c3a54d1 , < 0e243671bc7b8eaf00f83dd2f4367436dc0cff98 (git)	guessed
Linux	Linux	Affected: 2.6.19 Unaffected: 0 , < 2.6.19 (semver) Unaffected: 5.10.265 , ≤ 5.10.* (semver) Unaffected: 5.15.216 , ≤ 5.15.* (semver) Unaffected: 6.1.183 , ≤ 6.1.* (semver) Unaffected: 6.6.152 , ≤ 6.6.* (semver) Unaffected: 6.12.104 , ≤ 6.12.* (semver) Unaffected: 6.18.45 , ≤ 6.18.* (semver) Unaffected: 7.1.9 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)	guessed

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              "version": "5.10.265",
              "versionType": "semver"
            },
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              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.216",
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            },
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              "status": "unaffected",
              "version": "6.1.183",
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              "status": "unaffected",
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              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
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              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
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              "status": "unaffected",
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      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: prevent in6_dev_get() from resurrecting inet6_dev\n\nin6_dev_get() reads dev-\u003eip6_ptr under RCU and then unconditionally\nincrements its refcount. Device teardown can clear the pointer and drop\nthe last reference between these operations. The increment then\nresurrects an object whose RCU free has already been queued, so callers\ncan use it after it is freed.\n\nUse refcount_inc_not_zero() and return NULL when the object has already\nreached zero. RCU keeps the memory accessible through the attempted\nreference acquisition, and a successful increment pins the object for\nthe caller.\n\nAn independent run on the exact unpatched 6f5156d7a31a (v7.2-rc3)\nkernel reproduced the invalid reference acquisition as UID 1000:\n\n  refcount_t: addition on 0; use-after-free.\n  ip6_mc_source+0xef4/0x17e0\n\nIt was followed by the corresponding reference underflow in\nip6_mc_source(). The supplied trace from the same unpatched revision\nadditionally shows the access after the RCU read-side section ends:\n\n  BUG: KASAN: slab-use-after-free in mutex_lock+0x76/0xe0\n  Write of size 8 at addr ffff888015b50240 by task poc/1219\n\nBug found and triaged by OpenAI Security Research and\nvalidated by Trail of Bits."
        }
      ],
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            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
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              "lang": "en",
              "value": "AV:L - The reliable path is local setsockopt(2) on IPv6 MCAST source-filter options (ipv6_setsockopt \u2192 do_ipv6_mcast_group_source \u2192 ip6_mc_source \u2192 in6_dev_get), reproduced as UID 1000; concurrent netdev unregister is also a local rtnetlink syscall, not remote packet delivery.\nAC:L - An attacker in their own user+network namespace controls both sides of the race\u2014hammering MCAST_JOIN/BLOCK/UNBLOCK_SOURCE setsockopt while deleting the bound veth via RTM_DELLINK\u2014so the ip6_ptr clear and final in6_dev_put window is attacker-driven and retryable.\nPR:L - Multicast setsockopt needs no capability, but hitting the unregister teardown that drops the last inet6_dev reference requires CAP_NET_ADMIN for RTM_DELLINK; that is ns_capable() in the netns user_ns and is obtainable by an unprivileged user via unshare -Urn, not init-namespace root.\nUI:N - Exploitation uses only the attacker\u0027s own IPv6 sockets, setsockopt calls, and netdev create/delete in their namespace; no victim mount, click, or other cooperation is required.\nS:U - The resurrected inet6_dev UAF corrupts kernel heap state within the host kernel authority (mutex_lock on freed mc_lock); it is standard local kernel memory corruption, not a VM escape, IOMMU bypass, or other cross-boundary impact.\nC:H - Resurrecting a zero-refcount inet6_dev whose RCU free is already queued is a slab use-after-free; KASAN reported UAF on freed inet6_dev memory, and such heap UAFs enable disclosure via controlled reuse of the freed object.\nI:H - After resurrection the caller locks idev-\u003emc_lock and mutates multicast state on freed memory (KASAN write in mutex_lock), giving attacker-influenced heap corruption that can be turned into arbitrary write or control-flow hijack.\nA:H - The PoC triggers refcount_t addition-on-0 warnings, refcount underflow, and KASAN slab-use-after-free in mutex_lock, demonstrating immediate kernel memory corruption that can oops/panic and be repeated by re-running the race."
            }
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        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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          "url": "https://git.kernel.org/stable/c/785d908f8d21c8bc78b6fb2c2932ab662bf6918a"
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        {
          "url": "https://git.kernel.org/stable/c/0e243671bc7b8eaf00f83dd2f4367436dc0cff98"
        }
      ],
      "title": "ipv6: prevent in6_dev_get() from resurrecting inet6_dev",
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-74630",
    "datePublished": "2026-08-22T15:32:11.596Z",
    "dateReserved": "2026-08-15T05:44:03.921Z",
    "dateUpdated": "2026-08-25T05:40:54.475Z",
    "state": "PUBLISHED"
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      "date": "2026-08-24",
      "epss": "0.00177",
      "percentile": "0.07207"
    },
    "microsoft_vex": {
      "current_release_date": "2026-08-24T14:45:24.000Z",
      "cve": "CVE-2026-74630",
      "id": "msrc_CVE-2026-74630",
      "initial_release_date": "2026-08-24T01:01:57.000Z",
      "product_status:known_affected": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "ipv6: prevent in6_dev_get() from resurrecting inet6_dev",
      "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-74630.json",
      "version": "2"
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    "nvd": "{\"cve\":{\"id\":\"CVE-2026-74630\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-08-22T16:16:35.943\",\"lastModified\":\"2026-08-25T06:18:41.893\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nipv6: prevent in6_dev_get() from resurrecting inet6_dev\\n\\nin6_dev_get() reads dev-\u003eip6_ptr under RCU and then unconditionally\\nincrements its refcount. Device teardown can clear the pointer and drop\\nthe last reference between these operations. The increment then\\nresurrects an object whose RCU free has already been queued, so callers\\ncan use it after it is freed.\\n\\nUse refcount_inc_not_zero() and return NULL when the object has already\\nreached zero. RCU keeps the memory accessible through the attempted\\nreference acquisition, and a successful increment pins the object for\\nthe caller.\\n\\nAn independent run on the exact unpatched 6f5156d7a31a (v7.2-rc3)\\nkernel reproduced the invalid reference acquisition as UID 1000:\\n\\n  refcount_t: addition on 0; use-after-free.\\n  ip6_mc_source+0xef4/0x17e0\\n\\nIt was followed by the corresponding reference underflow in\\nip6_mc_source(). The supplied trace from the same unpatched revision\\nadditionally shows the access after the RCU read-side section ends:\\n\\n  BUG: KASAN: slab-use-after-free in mutex_lock+0x76/0xe0\\n  Write of size 8 at addr ffff888015b50240 by task poc/1219\\n\\nBug found and triaged by OpenAI Security Research and\\nvalidated by Trail of Bits.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"include/net/addrconf.h\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"8814c4b533817df825485ff32ce6ac406c3a54d1\",\"lessThan\":\"785d908f8d21c8bc78b6fb2c2932ab662bf6918a\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"8814c4b533817df825485ff32ce6ac406c3a54d1\",\"lessThan\":\"aedcfefdb5b7ed7f8a6196a3e68a25bdbe51d2f8\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"8814c4b533817df825485ff32ce6ac406c3a54d1\",\"lessThan\":\"145812b678de9f3b59780173be3c0d22ed60dd93\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"8814c4b533817df825485ff32ce6ac406c3a54d1\",\"lessThan\":\"cc5bd568f9b7683e60841b6fd02c10d64535bd6e\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"8814c4b533817df825485ff32ce6ac406c3a54d1\",\"lessThan\":\"1c206d461c680c3151daa3c89fc26eaf5bf98a7f\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"8814c4b533817df825485ff32ce6ac406c3a54d1\",\"lessThan\":\"680fbd7942185448eadb990a3d10a53eb946b702\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"8814c4b533817df825485ff32ce6ac406c3a54d1\",\"lessThan\":\"14e812ab41df0cac033479da835ec9a5de633404\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"8814c4b533817df825485ff32ce6ac406c3a54d1\",\"lessThan\":\"0e243671bc7b8eaf00f83dd2f4367436dc0cff98\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"include/net/addrconf.h\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"2.6.19\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"2.6.19\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.10.265\",\"lessThanOrEqual\":\"5.10.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.15.216\",\"lessThanOrEqual\":\"5.15.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.1.183\",\"lessThanOrEqual\":\"6.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.6.152\",\"lessThanOrEqual\":\"6.6.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.104\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.45\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.9\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":7.8,\"baseSeverity\":\"HIGH\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":5.9}]},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/0e243671bc7b8eaf00f83dd2f4367436dc0cff98\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/145812b678de9f3b59780173be3c0d22ed60dd93\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/14e812ab41df0cac033479da835ec9a5de633404\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/1c206d461c680c3151daa3c89fc26eaf5bf98a7f\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/680fbd7942185448eadb990a3d10a53eb946b702\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/785d908f8d21c8bc78b6fb2c2932ab662bf6918a\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/aedcfefdb5b7ed7f8a6196a3e68a25bdbe51d2f8\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/cc5bd568f9b7683e60841b6fd02c10d64535bd6e\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Important",
      "current_release_date": "2026-08-25T06:02:57+00:00",
      "cve": "CVE-2026-74630",
      "id": "CVE-2026-74630",
      "initial_release_date": "2026-08-22T00:00:00+00:00",
      "product_status:known_affected": "260",
      "product_status:under_investigation": "14",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: ipv6: prevent in6_dev_get() from resurrecting inet6_dev",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-74630.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "not set",
      "current_release_date": "2026-08-23T00:05:38Z",
      "cve": "CVE-2026-74630",
      "id": "CVE-2026-74630",
      "initial_release_date": "2026-08-23T00:05:38Z",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-74630",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-74630.json",
      "version": "2"
    }
  }
}

FKIE_CVE-2026-74630

Vulnerability from fkie_nvd - Published: 2026-08-22 16:16 - Updated: 2026-08-25 06:18

Severity

7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Summary

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/0e243671bc7b8eaf00f83dd2f4367436dc0cff98
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/145812b678de9f3b59780173be3c0d22ed60dd93
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/14e812ab41df0cac033479da835ec9a5de633404
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/1c206d461c680c3151daa3c89fc26eaf5bf98a7f
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/680fbd7942185448eadb990a3d10a53eb946b702
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/785d908f8d21c8bc78b6fb2c2932ab662bf6918a
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/aedcfefdb5b7ed7f8a6196a3e68a25bdbe51d2f8
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/cc5bd568f9b7683e60841b6fd02c10d64535bd6e

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "include/net/addrconf.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "785d908f8d21c8bc78b6fb2c2932ab662bf6918a",
              "status": "affected",
              "version": "8814c4b533817df825485ff32ce6ac406c3a54d1",
              "versionType": "git"
            },
            {
              "lessThan": "aedcfefdb5b7ed7f8a6196a3e68a25bdbe51d2f8",
              "status": "affected",
              "version": "8814c4b533817df825485ff32ce6ac406c3a54d1",
              "versionType": "git"
            },
            {
              "lessThan": "145812b678de9f3b59780173be3c0d22ed60dd93",
              "status": "affected",
              "version": "8814c4b533817df825485ff32ce6ac406c3a54d1",
              "versionType": "git"
            },
            {
              "lessThan": "cc5bd568f9b7683e60841b6fd02c10d64535bd6e",
              "status": "affected",
              "version": "8814c4b533817df825485ff32ce6ac406c3a54d1",
              "versionType": "git"
            },
            {
              "lessThan": "1c206d461c680c3151daa3c89fc26eaf5bf98a7f",
              "status": "affected",
              "version": "8814c4b533817df825485ff32ce6ac406c3a54d1",
              "versionType": "git"
            },
            {
              "lessThan": "680fbd7942185448eadb990a3d10a53eb946b702",
              "status": "affected",
              "version": "8814c4b533817df825485ff32ce6ac406c3a54d1",
              "versionType": "git"
            },
            {
              "lessThan": "14e812ab41df0cac033479da835ec9a5de633404",
              "status": "affected",
              "version": "8814c4b533817df825485ff32ce6ac406c3a54d1",
              "versionType": "git"
            },
            {
              "lessThan": "0e243671bc7b8eaf00f83dd2f4367436dc0cff98",
              "status": "affected",
              "version": "8814c4b533817df825485ff32ce6ac406c3a54d1",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "include/net/addrconf.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.19"
            },
            {
              "lessThan": "2.6.19",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.265",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.216",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.183",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.152",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.104",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.45",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.9",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: prevent in6_dev_get() from resurrecting inet6_dev\n\nin6_dev_get() reads dev-\u003eip6_ptr under RCU and then unconditionally\nincrements its refcount. Device teardown can clear the pointer and drop\nthe last reference between these operations. The increment then\nresurrects an object whose RCU free has already been queued, so callers\ncan use it after it is freed.\n\nUse refcount_inc_not_zero() and return NULL when the object has already\nreached zero. RCU keeps the memory accessible through the attempted\nreference acquisition, and a successful increment pins the object for\nthe caller.\n\nAn independent run on the exact unpatched 6f5156d7a31a (v7.2-rc3)\nkernel reproduced the invalid reference acquisition as UID 1000:\n\n  refcount_t: addition on 0; use-after-free.\n  ip6_mc_source+0xef4/0x17e0\n\nIt was followed by the corresponding reference underflow in\nip6_mc_source(). The supplied trace from the same unpatched revision\nadditionally shows the access after the RCU read-side section ends:\n\n  BUG: KASAN: slab-use-after-free in mutex_lock+0x76/0xe0\n  Write of size 8 at addr ffff888015b50240 by task poc/1219\n\nBug found and triaged by OpenAI Security Research and\nvalidated by Trail of Bits."
    }
  ],
  "id": "CVE-2026-74630",
  "lastModified": "2026-08-25T06:18:41.893",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-08-22T16:16:35.943",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0e243671bc7b8eaf00f83dd2f4367436dc0cff98"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/145812b678de9f3b59780173be3c0d22ed60dd93"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/14e812ab41df0cac033479da835ec9a5de633404"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/1c206d461c680c3151daa3c89fc26eaf5bf98a7f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/680fbd7942185448eadb990a3d10a53eb946b702"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/785d908f8d21c8bc78b6fb2c2932ab662bf6918a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/aedcfefdb5b7ed7f8a6196a3e68a25bdbe51d2f8"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/cc5bd568f9b7683e60841b6fd02c10d64535bd6e"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

GHSA-6G8V-5HWP-CMR2

Vulnerability from github – Published: 2026-08-22 18:30 – Updated: 2026-08-25 06:31

Details

In the Linux kernel, the following vulnerability has been resolved:

ipv6: prevent in6_dev_get() from resurrecting inet6_dev

in6_dev_get() reads dev->ip6_ptr under RCU and then unconditionally increments its refcount. Device teardown can clear the pointer and drop the last reference between these operations. The increment then resurrects an object whose RCU free has already been queued, so callers can use it after it is freed.

Use refcount_inc_not_zero() and return NULL when the object has already reached zero. RCU keeps the memory accessible through the attempted reference acquisition, and a successful increment pins the object for the caller.

An independent run on the exact unpatched 6f5156d7a31a (v7.2-rc3) kernel reproduced the invalid reference acquisition as UID 1000:

refcount_t: addition on 0; use-after-free. ip6_mc_source+0xef4/0x17e0

It was followed by the corresponding reference underflow in ip6_mc_source(). The supplied trace from the same unpatched revision additionally shows the access after the RCU read-side section ends:

BUG: KASAN: slab-use-after-free in mutex_lock+0x76/0xe0 Write of size 8 at addr ffff888015b50240 by task poc/1219

Bug found and triaged by OpenAI Security Research and validated by Trail of Bits.

Severity

7.8 (High)


                  
                    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-74630"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-22T16:16:35Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: prevent in6_dev_get() from resurrecting inet6_dev\n\nin6_dev_get() reads dev-\u003eip6_ptr under RCU and then unconditionally\nincrements its refcount. Device teardown can clear the pointer and drop\nthe last reference between these operations. The increment then\nresurrects an object whose RCU free has already been queued, so callers\ncan use it after it is freed.\n\nUse refcount_inc_not_zero() and return NULL when the object has already\nreached zero. RCU keeps the memory accessible through the attempted\nreference acquisition, and a successful increment pins the object for\nthe caller.\n\nAn independent run on the exact unpatched 6f5156d7a31a (v7.2-rc3)\nkernel reproduced the invalid reference acquisition as UID 1000:\n\n  refcount_t: addition on 0; use-after-free.\n  ip6_mc_source+0xef4/0x17e0\n\nIt was followed by the corresponding reference underflow in\nip6_mc_source(). The supplied trace from the same unpatched revision\nadditionally shows the access after the RCU read-side section ends:\n\n  BUG: KASAN: slab-use-after-free in mutex_lock+0x76/0xe0\n  Write of size 8 at addr ffff888015b50240 by task poc/1219\n\nBug found and triaged by OpenAI Security Research and\nvalidated by Trail of Bits.",
  "id": "GHSA-6g8v-5hwp-cmr2",
  "modified": "2026-08-25T06:31:24Z",
  "published": "2026-08-22T18:30:27Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74630"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0e243671bc7b8eaf00f83dd2f4367436dc0cff98"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/145812b678de9f3b59780173be3c0d22ed60dd93"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/14e812ab41df0cac033479da835ec9a5de633404"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1c206d461c680c3151daa3c89fc26eaf5bf98a7f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/680fbd7942185448eadb990a3d10a53eb946b702"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/785d908f8d21c8bc78b6fb2c2932ab662bf6918a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/aedcfefdb5b7ed7f8a6196a3e68a25bdbe51d2f8"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/cc5bd568f9b7683e60841b6fd02c10d64535bd6e"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

MSRC_CVE-2026-74630

Vulnerability from csaf_microsoft - Published: 2026-08-24 01:01 - Updated: 2026-08-24 14:45

Summary

ipv6: prevent in6_dev_get() from resurrecting inet6_dev

Notes

Additional Resources: To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle

Disclaimer: The information provided in the Microsoft Knowledge Base is provided \"as is\" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.

CVE-2026-74630

Affected products

Known affected 1 product

Product	Identifier	Version	Remediation
Unresolved product id: 17084-1		—	None Available

References

4 references

URL	Category
https://msrc.microsoft.com/csaf/vex/2026/msrc_cve…	self
https://support.microsoft.com/lifecycle	external
https://www.first.org/cvss	external
https://msrc.microsoft.com/csaf/vex/2026/msrc_cve…	self

JSON

To clipboard

{
  "document": {
    "category": "csaf_vex",
    "csaf_version": "2.0",
    "distribution": {
      "text": "Public",
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
      }
    },
    "lang": "en-US",
    "notes": [
      {
        "category": "general",
        "text": "To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle",
        "title": "Additional Resources"
      },
      {
        "category": "legal_disclaimer",
        "text": "The information provided in the Microsoft Knowledge Base is provided \\\"as is\\\" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.",
        "title": "Disclaimer"
      }
    ],
    "publisher": {
      "category": "vendor",
      "contact_details": "secure@microsoft.com",
      "name": "Microsoft Security Response Center",
      "namespace": "https://msrc.microsoft.com"
    },
    "references": [
      {
        "category": "self",
        "summary": "CVE-2026-74630 ipv6: prevent in6_dev_get() from resurrecting inet6_dev - VEX",
        "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-74630.json"
      },
      {
        "category": "external",
        "summary": "Microsoft Support Lifecycle",
        "url": "https://support.microsoft.com/lifecycle"
      },
      {
        "category": "external",
        "summary": "Common Vulnerability Scoring System",
        "url": "https://www.first.org/cvss"
      }
    ],
    "title": "ipv6: prevent in6_dev_get() from resurrecting inet6_dev",
    "tracking": {
      "current_release_date": "2026-08-24T14:45:24.000Z",
      "generator": {
        "date": "2026-08-25T07:02:58.279Z",
        "engine": {
          "name": "MSRC Generator",
          "version": "1.0"
        }
      },
      "id": "msrc_CVE-2026-74630",
      "initial_release_date": "2026-08-24T01:01:57.000Z",
      "revision_history": [
        {
          "date": "2026-08-24T01:01:57.000Z",
          "legacy_version": "1",
          "number": "1",
          "summary": "Information published."
        },
        {
          "date": "2026-08-24T14:45:24.000Z",
          "legacy_version": "2",
          "number": "2",
          "summary": "Information published."
        }
      ],
      "status": "final",
      "version": "2"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_version",
                "name": "3.0",
                "product": {
                  "name": "Azure Linux 3.0",
                  "product_id": "17084"
                }
              }
            ],
            "category": "product_name",
            "name": "Azure Linux"
          },
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "azl3 kernel 0:6.6.150.1-1.azl3",
                "product": {
                  "name": "azl3 kernel 0:6.6.150.1-1.azl3",
                  "product_id": "1"
                }
              }
            ],
            "category": "product_name",
            "name": "kernel"
          }
        ],
        "category": "vendor",
        "name": "Microsoft"
      }
    ],
    "relationships": [
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "azl3 kernel 0:6.6.150.1-1.azl3 as a component of Azure Linux 3.0",
          "product_id": "17084-1"
        },
        "product_reference": "1",
        "relates_to_product_reference": "17084"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-74630",
      "notes": [
        {
          "category": "general",
          "text": "Linux",
          "title": "Assigning CNA"
        }
      ],
      "product_status": {
        "known_affected": [
          "17084-1"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2026-74630 ipv6: prevent in6_dev_get() from resurrecting inet6_dev - VEX",
          "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-74630.json"
        }
      ],
      "remediations": [
        {
          "category": "none_available",
          "date": "2026-08-24T01:01:57.000Z",
          "details": "There is no fix available for this vulnerability as of now",
          "product_ids": [
            "17084-1"
          ]
        }
      ],
      "title": "ipv6: prevent in6_dev_get() from resurrecting inet6_dev"
    }
  ]
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

Action not permitted

CVE-2026-74630 (GCVE-0-2026-74630)

FKIE_CVE-2026-74630

GHSA-6G8V-5HWP-CMR2

MSRC_CVE-2026-74630

Tags

Sightings

Nomenclature