GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

CVE-2026-64414 (GCVE-0-2026-64414)

Vulnerability from cvelistv5 – Published: 2026-07-25 08:50 – Updated: 2026-08-17 04:55
VLAI
Title
netfilter: handle unreadable frags
Summary
In the Linux kernel, the following vulnerability has been resolved: netfilter: handle unreadable frags sashiko reports: When an skb with unreadable fragments (such as from devmem TCP, where skb_frags_readable(skb) returns false) is processed by the u32 module, skb_copy_bits() will safely return a negative error code [..] xt_u32: bail out with hotdrop in this case. gather_frags: return -1, just as if we had no fragment header. nfnetlink_queue: restrict to the linear part. nfnetlink_log: restrict to the linear part. v2: - skb_zerocopy helpers don't copy readable flag, i.e. nfnetlink_queue is broken too xt_u32 shouldn't return true if hotdrop was set.
Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 65249feb6b3df9e17bab5911ee56fa7b0971e231 , < 3b13e7635795394705920cca1e1db7e4ca2e334b (git)
Affected: 65249feb6b3df9e17bab5911ee56fa7b0971e231 , < fc5bfe63bacf8a3ae307b62b34206406ca733354 (git)
Affected: 65249feb6b3df9e17bab5911ee56fa7b0971e231 , < 57056be3ec12e7d9ecd20a60d4060f510e4f284c (git)
Affected: 65249feb6b3df9e17bab5911ee56fa7b0971e231 , < da5b58478a9c1b85608c9e40a3b8432d071b409e (git)
guessed Create a notification for this product.
Linux Linux Affected: 6.12
Unaffected: 0 , < 6.12 (semver)
Unaffected: 6.12.96 , ≤ 6.12.* (semver)
Unaffected: 6.18.39 , ≤ 6.18.* (semver)
Unaffected: 7.1.4 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/ipv6/netfilter/nf_conntrack_reasm.c",
            "net/netfilter/nfnetlink_log.c",
            "net/netfilter/nfnetlink_queue.c",
            "net/netfilter/xt_u32.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "3b13e7635795394705920cca1e1db7e4ca2e334b",
              "status": "affected",
              "version": "65249feb6b3df9e17bab5911ee56fa7b0971e231",
              "versionType": "git"
            },
            {
              "lessThan": "fc5bfe63bacf8a3ae307b62b34206406ca733354",
              "status": "affected",
              "version": "65249feb6b3df9e17bab5911ee56fa7b0971e231",
              "versionType": "git"
            },
            {
              "lessThan": "57056be3ec12e7d9ecd20a60d4060f510e4f284c",
              "status": "affected",
              "version": "65249feb6b3df9e17bab5911ee56fa7b0971e231",
              "versionType": "git"
            },
            {
              "lessThan": "da5b58478a9c1b85608c9e40a3b8432d071b409e",
              "status": "affected",
              "version": "65249feb6b3df9e17bab5911ee56fa7b0971e231",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/ipv6/netfilter/nf_conntrack_reasm.c",
            "net/netfilter/nfnetlink_log.c",
            "net/netfilter/nfnetlink_queue.c",
            "net/netfilter/xt_u32.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.12"
            },
            {
              "lessThan": "6.12",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.96",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.39",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.96",
                  "versionStartIncluding": "6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.39",
                  "versionStartIncluding": "6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.4",
                  "versionStartIncluding": "6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "6.12",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: handle unreadable frags\n\nsashiko reports:\n When an skb with unreadable fragments (such as from devmem TCP, where\n skb_frags_readable(skb) returns false) is processed by the u32 module,\n skb_copy_bits() will safely return a negative error code [..]\n\nxt_u32: bail out with hotdrop in this case.\ngather_frags: return -1, just as if we had no fragment header.\nnfnetlink_queue: restrict to the linear part.\nnfnetlink_log: restrict to the linear part.\n\nv2:\n - skb_zerocopy helpers don\u0027t copy readable flag, i.e. nfnetlink_queue\n is broken too\n xt_u32 shouldn\u0027t return true if hotdrop was set."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - Unreadable skbs arise on the receive side of device-memory TCP, and a remote peer can send packets that traverse netfilter hooks into u32, NFLOG, NFQUEUE, or IPv6 conntrack defragmentation. No local access is required in a network-exposed devmem TCP deployment.\nAC:L - Once devmem/header-split RX and an affected netfilter path are active, a sufficiently long payload or crafted IPv6 extension/fragment layout reliably reaches unreadable fragments. There is no race or condition the attacker must win, and triggering packets can be sent repeatedly.\nPR:N - The triggering packets are processed before application authentication, so the remote peer needs no account or kernel capability. CAP_NET_ADMIN is required for the operator\u0027s device and netfilter configuration, not for the attacker sending packets.\nUI:N - Packet reception and netfilter processing occur automatically without any victim action after the service and policy are configured.\nS:U - The resulting failure affects the same host kernel and does not cross a VM, IOMMU, or other distinct security authority boundary.\nC:N - skb_copy_bits() rejects the unreadable fragments before accessing their contents, while the NFQUEUE flag-loss path reaches an invalid page mapping. No attacker-accessible information-disclosure primitive was identified.\nI:N - The vulnerability causes BUG or invalid-access paths but provides no out-of-bounds write, use-after-free, type confusion, or attacker-controlled data modification.\nA:H - The u32, NFLOG, and IPv6 paths execute BUG(), and the NFQUEUE path can dereference an invalid page during netlink recvmsg. These can produce a kernel oops or panic and can be triggered repeatedly."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T04:55:13.439Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/3b13e7635795394705920cca1e1db7e4ca2e334b"
        },
        {
          "url": "https://git.kernel.org/stable/c/fc5bfe63bacf8a3ae307b62b34206406ca733354"
        },
        {
          "url": "https://git.kernel.org/stable/c/57056be3ec12e7d9ecd20a60d4060f510e4f284c"
        },
        {
          "url": "https://git.kernel.org/stable/c/da5b58478a9c1b85608c9e40a3b8432d071b409e"
        }
      ],
      "title": "netfilter: handle unreadable frags",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64414",
    "datePublished": "2026-07-25T08:50:54.495Z",
    "dateReserved": "2026-07-19T15:36:31.786Z",
    "dateUpdated": "2026-08-17T04:55:13.439Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-64414",
      "date": "2026-09-16",
      "epss": "0.00441",
      "percentile": "0.37472"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-64414\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-07-25T10:17:25.237\",\"lastModified\":\"2026-09-04T15:26:15.600\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nnetfilter: handle unreadable frags\\n\\nsashiko reports:\\n When an skb with unreadable fragments (such as from devmem TCP, where\\n skb_frags_readable(skb) returns false) is processed by the u32 module,\\n skb_copy_bits() will safely return a negative error code [..]\\n\\nxt_u32: bail out with hotdrop in this case.\\ngather_frags: return -1, just as if we had no fragment header.\\nnfnetlink_queue: restrict to the linear part.\\nnfnetlink_log: restrict to the linear part.\\n\\nv2:\\n - skb_zerocopy helpers don\u0027t copy readable flag, i.e. nfnetlink_queue\\n is broken too\\n xt_u32 shouldn\u0027t return true if hotdrop was set.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"net/ipv6/netfilter/nf_conntrack_reasm.c\",\"net/netfilter/nfnetlink_log.c\",\"net/netfilter/nfnetlink_queue.c\",\"net/netfilter/xt_u32.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"65249feb6b3df9e17bab5911ee56fa7b0971e231\",\"lessThan\":\"3b13e7635795394705920cca1e1db7e4ca2e334b\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"65249feb6b3df9e17bab5911ee56fa7b0971e231\",\"lessThan\":\"fc5bfe63bacf8a3ae307b62b34206406ca733354\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"65249feb6b3df9e17bab5911ee56fa7b0971e231\",\"lessThan\":\"57056be3ec12e7d9ecd20a60d4060f510e4f284c\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"65249feb6b3df9e17bab5911ee56fa7b0971e231\",\"lessThan\":\"da5b58478a9c1b85608c9e40a3b8432d071b409e\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"net/ipv6/netfilter/nf_conntrack_reasm.c\",\"net/netfilter/nfnetlink_log.c\",\"net/netfilter/nfnetlink_queue.c\",\"net/netfilter/xt_u32.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"6.12\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"6.12\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.96\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.39\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.4\",\"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:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":7.5,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":3.9,\"impactScore\":3.6}]},\"weaknesses\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"NVD-CWE-noinfo\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.12\",\"versionEndExcluding\":\"6.12.96\",\"matchCriteriaId\":\"2F44D3FC-139F-4CA5-8124-010E2F6B3AA0\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.13\",\"versionEndExcluding\":\"6.18.39\",\"matchCriteriaId\":\"914AE4BC-3D59-4C5A-9DB5-9CE327B429F7\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.19\",\"versionEndExcluding\":\"7.1.4\",\"matchCriteriaId\":\"6228DDD6-4557-4AA3-9F43-AB995D471E42\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:7.2:rc1:*:*:*:*:*:*\",\"matchCriteriaId\":\"5E8B9085-7ADB-4A05-89EF-12949B6A0509\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:7.2:rc2:*:*:*:*:*:*\",\"matchCriteriaId\":\"1FC0D50D-9D58-4947-A197-A5A3FF07E7E3\"}]}]}],\"references\":[{\"url\":\"https://git.kernel.org/stable/c/3b13e7635795394705920cca1e1db7e4ca2e334b\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/57056be3ec12e7d9ecd20a60d4060f510e4f284c\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/da5b58478a9c1b85608c9e40a3b8432d071b409e\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/fc5bfe63bacf8a3ae307b62b34206406ca733354\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-07-30T08:27:44+00:00",
      "cve": "CVE-2026-64414",
      "id": "CVE-2026-64414",
      "initial_release_date": "2026-07-25T00:00:00+00:00",
      "product_status:known_affected": "90",
      "product_status:known_not_affected": "184",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: netfilter: handle unreadable frags",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-64414.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-09-15T01:49:26Z",
      "cve": "CVE-2026-64414",
      "id": "CVE-2026-64414",
      "initial_release_date": "2026-07-25T15:59:47Z",
      "product_status:known_affected": "29",
      "product_status:known_not_affected": "347",
      "product_status:recommended": "4",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-64414",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-64414.json",
      "version": "7"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.


Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.