Vulnerability-Lookup

GHSA-3FQJ-WV67-HQ22

Vulnerability from github – Published: 2026-08-15 06:32 – Updated: 2026-08-17 06:33

Details

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

ipvs: reload ip header after head reallocation

__ip_vs_get_out_rt() calls skb_ensure_writable() which may reallocate skb->head.

Severity

9.8 (Critical)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-68476"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-15T06:20:41Z",
    "severity": "CRITICAL"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nipvs: reload ip header after head reallocation\n\n__ip_vs_get_out_rt() calls skb_ensure_writable() which may\nreallocate skb-\u003ehead.",
  "id": "GHSA-3fqj-wv67-hq22",
  "modified": "2026-08-17T06:33:03Z",
  "published": "2026-08-15T06:32:08Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-68476"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3fb7edd2018bb1ad0a68157383d9b9dac33dd645"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a2f57827bf7c695b8c72dc4511cae8e86582369d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ac6ac3d35bfc0ade9d17d354c84e503a946ebdab"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ad1e14710b360bda087ebf9fb82460eb5ef775de"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e51687fc56c2e39ea6e9532925f1aabd4d529f61"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-68476 (GCVE-0-2026-68476)

Vulnerability from cvelistv5 – Published: 2026-08-15 05:51 – Updated: 2026-08-17 05:39

Title

ipvs: reload ip header after head reallocation

Summary

In the Linux kernel, the following vulnerability has been resolved: ipvs: reload ip header after head reallocation __ip_vs_get_out_rt() calls skb_ensure_writable() which may reallocate skb->head.

Severity

9.8 (Critical)


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

Assigner

Linux mitre root

References

5 references

URL	Tags
https://git.kernel.org/stable/c/ac6ac3d35bfc0ade9…
https://git.kernel.org/stable/c/e51687fc56c2e39ea…
https://git.kernel.org/stable/c/3fb7edd2018bb1ad0…
https://git.kernel.org/stable/c/ad1e14710b360bda0…
https://git.kernel.org/stable/c/a2f57827bf7c695b8…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 8d8e20e2d7bba8c50e64e0eca1cb83956f468e49 , < ac6ac3d35bfc0ade9d17d354c84e503a946ebdab (git) Affected: 8d8e20e2d7bba8c50e64e0eca1cb83956f468e49 , < e51687fc56c2e39ea6e9532925f1aabd4d529f61 (git) Affected: 8d8e20e2d7bba8c50e64e0eca1cb83956f468e49 , < 3fb7edd2018bb1ad0a68157383d9b9dac33dd645 (git) Affected: 8d8e20e2d7bba8c50e64e0eca1cb83956f468e49 , < ad1e14710b360bda087ebf9fb82460eb5ef775de (git) Affected: 8d8e20e2d7bba8c50e64e0eca1cb83956f468e49 , < a2f57827bf7c695b8c72dc4511cae8e86582369d (git)
Linux	Linux	Affected: 4.10 Unaffected: 0 , < 4.10 (semver) Unaffected: 6.6.145 , ≤ 6.6.* (semver) Unaffected: 6.12.97 , ≤ 6.12.* (semver) Unaffected: 6.18.40 , ≤ 6.18.* (semver) Unaffected: 7.1.5 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/netfilter/ipvs/ip_vs_xmit.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "ac6ac3d35bfc0ade9d17d354c84e503a946ebdab",
              "status": "affected",
              "version": "8d8e20e2d7bba8c50e64e0eca1cb83956f468e49",
              "versionType": "git"
            },
            {
              "lessThan": "e51687fc56c2e39ea6e9532925f1aabd4d529f61",
              "status": "affected",
              "version": "8d8e20e2d7bba8c50e64e0eca1cb83956f468e49",
              "versionType": "git"
            },
            {
              "lessThan": "3fb7edd2018bb1ad0a68157383d9b9dac33dd645",
              "status": "affected",
              "version": "8d8e20e2d7bba8c50e64e0eca1cb83956f468e49",
              "versionType": "git"
            },
            {
              "lessThan": "ad1e14710b360bda087ebf9fb82460eb5ef775de",
              "status": "affected",
              "version": "8d8e20e2d7bba8c50e64e0eca1cb83956f468e49",
              "versionType": "git"
            },
            {
              "lessThan": "a2f57827bf7c695b8c72dc4511cae8e86582369d",
              "status": "affected",
              "version": "8d8e20e2d7bba8c50e64e0eca1cb83956f468e49",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/netfilter/ipvs/ip_vs_xmit.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.10"
            },
            {
              "lessThan": "4.10",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.145",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.97",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.40",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "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": "6.6.145",
                  "versionStartIncluding": "4.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.97",
                  "versionStartIncluding": "4.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.40",
                  "versionStartIncluding": "4.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.5",
                  "versionStartIncluding": "4.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "4.10",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipvs: reload ip header after head reallocation\n\n__ip_vs_get_out_rt() calls skb_ensure_writable() which may\nreallocate skb-\u003ehead."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 9.8,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - The flaw is in ip_vs_bypass_xmit() on the IPVS netfilter receive path (NF_INET_LOCAL_IN/FORWARD); remote IPv4 packets to a configured virtual-server VIP reach ip_vs_in_hook() and ip_vs_leave() without local syscalls or ioctl.\nAC:L - Once cache_bypass is enabled on a fwmark IPVS service with no backend, an attacker can repeatedly send traffic to the VIP; cloned skbs (common with bridging, mirroring, or shared receive buffers) make skb_ensure_writable() reallocate skb-\u003ehead deterministically.\nPR:N - Exploitation requires only sending IP packets to the load balancer VIP; IPVS/cache_bypass configuration is an operator prerequisite on the target, not a Linux capability the remote attacker must hold.\nUI:N - No victim interaction is required; kernel processing of attacker-crafted network packets on the IPVS bypass transmit path alone triggers the stale header pointer use after skb head reallocation.\nS:U - Impact is kernel heap corruption and load-balancer compromise within the host kernel security domain; it does not cross VM, container, or IOMMU boundaries to another security authority.\nC:H - After pskb_expand_head() frees the old skb-\u003ehead, ip_send_check() uses the stale iph pointer and ip_fast_csum() reads attacker-influenced bytes from freed kmalloc memory, a classic use-after-free information disclosure primitive.\nI:H - ip_send_check() writes through the stale iph pointer (zeroing and updating the checksum field) into freed/reallocated slab memory, enabling heap corruption and potential arbitrary kernel write or control-flow hijack primitives.\nA:H - Writing and reading through a stale IP header pointer after skb head reallocation can corrupt adjacent kernel heap objects or dereference freed memory, causing kernel oops, panic, or hang and repeatable denial of service."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:39:18.386Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/ac6ac3d35bfc0ade9d17d354c84e503a946ebdab"
        },
        {
          "url": "https://git.kernel.org/stable/c/e51687fc56c2e39ea6e9532925f1aabd4d529f61"
        },
        {
          "url": "https://git.kernel.org/stable/c/3fb7edd2018bb1ad0a68157383d9b9dac33dd645"
        },
        {
          "url": "https://git.kernel.org/stable/c/ad1e14710b360bda087ebf9fb82460eb5ef775de"
        },
        {
          "url": "https://git.kernel.org/stable/c/a2f57827bf7c695b8c72dc4511cae8e86582369d"
        }
      ],
      "title": "ipvs: reload ip header after head reallocation",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-68476",
    "datePublished": "2026-08-15T05:51:32.170Z",
    "dateReserved": "2026-07-30T09:28:09.396Z",
    "dateUpdated": "2026-08-17T05:39:18.386Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

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GHSA-3FQJ-WV67-HQ22

CVE-2026-68476 (GCVE-0-2026-68476)

Tags

Sightings

Nomenclature