Vulnerability-Lookup

GHSA-5W2V-4J6C-44H8

Vulnerability from github – Published: 2026-07-19 18:31 – Updated: 2026-07-28 15:32

Details

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

ipv6: exthdrs: refresh nh after handling HAO option

ip6_parse_tlv() caches skb_network_header(skb) in nh while walking IPv6 TLVs.

ipv6_dest_hao() may call pskb_expand_head() for a cloned skb, which can move the skb head and invalidate the cached network header pointer. Refresh nh after ipv6_dest_hao() returns so any trailing padding or TLVs are parsed from the current skb head.

This matches the existing pattern used in ip6_parse_tlv() after helpers that can modify skb header storage.

Severity

9.8 (Critical)


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

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-63922"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-19T16:17:10Z",
    "severity": "CRITICAL"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: exthdrs: refresh nh after handling HAO option\n\nip6_parse_tlv() caches skb_network_header(skb) in nh while walking\nIPv6 TLVs.\n\nipv6_dest_hao() may call pskb_expand_head() for a cloned skb, which can\nmove the skb head and invalidate the cached network header pointer.\nRefresh nh after ipv6_dest_hao() returns so any trailing padding or TLVs\nare parsed from the current skb head.\n\nThis matches the existing pattern used in ip6_parse_tlv() after helpers\nthat can modify skb header storage.",
  "id": "GHSA-5w2v-4j6c-44h8",
  "modified": "2026-07-28T15:32:04Z",
  "published": "2026-07-19T18:31:46Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-63922"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/12d957979e4a800167842f1b42be6a606d227ebe"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1a11eb7431e3d2882f5bd5939c5a9bbc65ccf4d1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/751db1b802a067b7fff25880f4e9f9152a171538"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9b6dcc0a39fd71752937f0b6b3973e1416085dcf"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b3ac54e5c905f86d22b502eacb5686a282c5659f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f7b52afe3592eae66e160586b45a3f2242972c63"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f8aabed3ff3e986920cf02a2a2785e08e586b234"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ff375ed1cba81392346c5bfbf0bb7a13b2946f99"
    }
  ],
  "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-2026-63922 (GCVE-0-2026-63922)

Vulnerability from cvelistv5 – Published: 2026-07-19 14:55 – Updated: 2026-08-05 12:37

Title

ipv6: exthdrs: refresh nh after handling HAO option

Summary

In the Linux kernel, the following vulnerability has been resolved: ipv6: exthdrs: refresh nh after handling HAO option ip6_parse_tlv() caches skb_network_header(skb) in nh while walking IPv6 TLVs. ipv6_dest_hao() may call pskb_expand_head() for a cloned skb, which can move the skb head and invalidate the cached network header pointer. Refresh nh after ipv6_dest_hao() returns so any trailing padding or TLVs are parsed from the current skb head. This matches the existing pattern used in ip6_parse_tlv() after helpers that can modify skb header storage.

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 Scorecard

References

8 references

URL	Tags
https://git.kernel.org/stable/c/b3ac54e5c905f86d2…
https://git.kernel.org/stable/c/f8aabed3ff3e98692…
https://git.kernel.org/stable/c/1a11eb7431e3d2882…
https://git.kernel.org/stable/c/12d957979e4a80016…
https://git.kernel.org/stable/c/ff375ed1cba813923…
https://git.kernel.org/stable/c/751db1b802a067b7f…
https://git.kernel.org/stable/c/9b6dcc0a39fd71752…
https://git.kernel.org/stable/c/f7b52afe3592eae66…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: a831f5bbc89a9978795504be9e1ff412043f8f77 , < b3ac54e5c905f86d22b502eacb5686a282c5659f (git) Affected: a831f5bbc89a9978795504be9e1ff412043f8f77 , < f8aabed3ff3e986920cf02a2a2785e08e586b234 (git) Affected: a831f5bbc89a9978795504be9e1ff412043f8f77 , < 1a11eb7431e3d2882f5bd5939c5a9bbc65ccf4d1 (git) Affected: a831f5bbc89a9978795504be9e1ff412043f8f77 , < 12d957979e4a800167842f1b42be6a606d227ebe (git) Affected: a831f5bbc89a9978795504be9e1ff412043f8f77 , < ff375ed1cba81392346c5bfbf0bb7a13b2946f99 (git) Affected: a831f5bbc89a9978795504be9e1ff412043f8f77 , < 751db1b802a067b7fff25880f4e9f9152a171538 (git) Affected: a831f5bbc89a9978795504be9e1ff412043f8f77 , < 9b6dcc0a39fd71752937f0b6b3973e1416085dcf (git) Affected: a831f5bbc89a9978795504be9e1ff412043f8f77 , < f7b52afe3592eae66e160586b45a3f2242972c63 (git)
Linux	Linux	Affected: 2.6.19 Unaffected: 0 , < 2.6.19 (semver) Unaffected: 5.10.259 , ≤ 5.10.* (semver) Unaffected: 5.15.210 , ≤ 5.15.* (semver) Unaffected: 6.1.176 , ≤ 6.1.* (semver) Unaffected: 6.6.143 , ≤ 6.6.* (semver) Unaffected: 6.12.93 , ≤ 6.12.* (semver) Unaffected: 6.18.35 , ≤ 6.18.* (semver) Unaffected: 7.0.12 , ≤ 7.0.* (semver) Unaffected: 7.1 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/ipv6/exthdrs.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "b3ac54e5c905f86d22b502eacb5686a282c5659f",
              "status": "affected",
              "version": "a831f5bbc89a9978795504be9e1ff412043f8f77",
              "versionType": "git"
            },
            {
              "lessThan": "f8aabed3ff3e986920cf02a2a2785e08e586b234",
              "status": "affected",
              "version": "a831f5bbc89a9978795504be9e1ff412043f8f77",
              "versionType": "git"
            },
            {
              "lessThan": "1a11eb7431e3d2882f5bd5939c5a9bbc65ccf4d1",
              "status": "affected",
              "version": "a831f5bbc89a9978795504be9e1ff412043f8f77",
              "versionType": "git"
            },
            {
              "lessThan": "12d957979e4a800167842f1b42be6a606d227ebe",
              "status": "affected",
              "version": "a831f5bbc89a9978795504be9e1ff412043f8f77",
              "versionType": "git"
            },
            {
              "lessThan": "ff375ed1cba81392346c5bfbf0bb7a13b2946f99",
              "status": "affected",
              "version": "a831f5bbc89a9978795504be9e1ff412043f8f77",
              "versionType": "git"
            },
            {
              "lessThan": "751db1b802a067b7fff25880f4e9f9152a171538",
              "status": "affected",
              "version": "a831f5bbc89a9978795504be9e1ff412043f8f77",
              "versionType": "git"
            },
            {
              "lessThan": "9b6dcc0a39fd71752937f0b6b3973e1416085dcf",
              "status": "affected",
              "version": "a831f5bbc89a9978795504be9e1ff412043f8f77",
              "versionType": "git"
            },
            {
              "lessThan": "f7b52afe3592eae66e160586b45a3f2242972c63",
              "status": "affected",
              "version": "a831f5bbc89a9978795504be9e1ff412043f8f77",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/ipv6/exthdrs.c"
          ],
          "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": "5.10.259",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.210",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.176",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.143",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.93",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.35",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.12",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.259",
                  "versionStartIncluding": "2.6.19",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.210",
                  "versionStartIncluding": "2.6.19",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.176",
                  "versionStartIncluding": "2.6.19",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.143",
                  "versionStartIncluding": "2.6.19",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.93",
                  "versionStartIncluding": "2.6.19",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.35",
                  "versionStartIncluding": "2.6.19",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0.12",
                  "versionStartIncluding": "2.6.19",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1",
                  "versionStartIncluding": "2.6.19",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: exthdrs: refresh nh after handling HAO option\n\nip6_parse_tlv() caches skb_network_header(skb) in nh while walking\nIPv6 TLVs.\n\nipv6_dest_hao() may call pskb_expand_head() for a cloned skb, which can\nmove the skb head and invalidate the cached network header pointer.\nRefresh nh after ipv6_dest_hao() returns so any trailing padding or TLVs\nare parsed from the current skb head.\n\nThis matches the existing pattern used in ip6_parse_tlv() after helpers\nthat can modify skb header storage."
        }
      ],
      "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 bug is reached on the standard IPv6 input path (ipv6_rcv \u2192 ip6_input \u2192 ip6_protocol_deliver_rcu \u2192 ipv6_destopt_rcv) when a remotely sent IPv6 packet carries a Destination Options header processed by ip6_parse_tlv().\nAC:L - The attacker fully controls the crafted IPv6 Destination Options layout (HAO TLV followed by trailing TLVs/padding); once CONFIG_IPV6_MIP6 and matching XFRM state exist on the target, triggering the stale-pointer condition is a reliable single-packet attack without races or victim-specific timing.\nPR:N - No local privileges or authentication are required; any remote host that can deliver IPv6 traffic to a listening interface can reach this pre-authentication receive-path parser (destopt_protocol uses INET6_PROTO_NOPOLICY).\nUI:N - Exploitation requires only sending a malicious IPv6 packet; no victim interaction such as opening files, clicking links, or mounting filesystems is needed.\nS:U - Impact is confined to kernel memory corruption and privilege escalation within the kernel\u2019s security authority; it does not cross VM, container, or IOMMU boundaries.\nC:H - After pskb_expand_head() frees the old skb head, ip6_parse_tlv() continues parsing trailing TLVs through the stale nh pointer, causing out-of-bounds/use-after-free reads of kernel heap memory that can disclose sensitive kernel data.\nI:H - Use-after-free of the skb head buffer during TLV parsing is heap memory corruption that can be leveraged for arbitrary kernel writes and control-flow hijacking, not merely a bounded parse error.\nA:H - Reading through the stale network-header pointer into freed or invalid memory can cause kernel oops/panic or unrecoverable instability, satisfying high availability impact even before full exploitation."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T12:37:16.967Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/b3ac54e5c905f86d22b502eacb5686a282c5659f"
        },
        {
          "url": "https://git.kernel.org/stable/c/f8aabed3ff3e986920cf02a2a2785e08e586b234"
        },
        {
          "url": "https://git.kernel.org/stable/c/1a11eb7431e3d2882f5bd5939c5a9bbc65ccf4d1"
        },
        {
          "url": "https://git.kernel.org/stable/c/12d957979e4a800167842f1b42be6a606d227ebe"
        },
        {
          "url": "https://git.kernel.org/stable/c/ff375ed1cba81392346c5bfbf0bb7a13b2946f99"
        },
        {
          "url": "https://git.kernel.org/stable/c/751db1b802a067b7fff25880f4e9f9152a171538"
        },
        {
          "url": "https://git.kernel.org/stable/c/9b6dcc0a39fd71752937f0b6b3973e1416085dcf"
        },
        {
          "url": "https://git.kernel.org/stable/c/f7b52afe3592eae66e160586b45a3f2242972c63"
        }
      ],
      "title": "ipv6: exthdrs: refresh nh after handling HAO option",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-63922",
    "datePublished": "2026-07-19T14:55:24.268Z",
    "dateReserved": "2026-07-19T07:54:57.021Z",
    "dateUpdated": "2026-08-05T12:37:16.967Z",
    "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.

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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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.

Action not permitted

GHSA-5W2V-4J6C-44H8

CVE-2026-63922 (GCVE-0-2026-63922)

Tags

Sightings

Nomenclature

Related by attack behaviour