CVE-2026-97940

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: ipv6: fix fib6 walker UAF on seq stop ipv6_route_iter_active() treats a walker in FWS_U at the table root as already unlinked. fib6_del_route() can move a still-linked walker into that same state when the current leaf is the last route at the root, so ipv6_route_native_seq_stop() skips fib6_walker_unlink(). The seq private object can then be freed while it remains on net->ipv6.fib6_walkers. A later route deletion walks the dangling list and uses the freed walker. Use the list head as membership state and reinitialize it when unlinking. Keep the existing w->node check so a never-started iterator with a zeroed private object is not treated as linked. The same stop helper is used by /proc/net/ipv6_route and by the BPF ipv6_route iterator. The BPF show path only widens the race.

Severity

HIGH

CVSS score

7.8 (v3.1)

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-09-25 11:17:21.410000

Last modified

2026-10-19 10:17:45.110000

View original CVE JSON

{
  "id": "CVE-2026-97940",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-09-25T11:17:21.410",
  "lastModified": "2026-10-19T10:17:45.110",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: fix fib6 walker UAF on seq stop\n\nipv6_route_iter_active() treats a walker in FWS_U at the table root as\nalready unlinked. fib6_del_route() can move a still-linked walker into\nthat same state when the current leaf is the last route at the root,\nso ipv6_route_native_seq_stop() skips fib6_walker_unlink(). The seq\nprivate object can then be freed while it remains on\nnet->ipv6.fib6_walkers. A later route deletion walks the dangling list\nand uses the freed walker.\n\nUse the list head as membership state and reinitialize it when\nunlinking. Keep the existing w->node check so a never-started iterator\nwith a zeroed private object is not treated as linked.\n\nThe same stop helper is used by /proc/net/ipv6_route and by the BPF\nipv6_route iterator. The BPF show path only widens the race."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "net/ipv6/ip6_fib.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "8d2ca1d7b5c3e63b3a8a81ae99015b615c5f2bf7",
              "lessThan": "9a3f73d62c86271614eda4c43315230896a37018",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "8d2ca1d7b5c3e63b3a8a81ae99015b615c5f2bf7",
              "lessThan": "63407cddabc5992b5ac03af165559f4a1968a032",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "8d2ca1d7b5c3e63b3a8a81ae99015b615c5f2bf7",
              "lessThan": "05b687ee04f816658f4a9cf586f4d2f129157943",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "8d2ca1d7b5c3e63b3a8a81ae99015b615c5f2bf7",
              "lessThan": "14fdaba201fdff92a3e45994e02bccda409cb19d",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "8d2ca1d7b5c3e63b3a8a81ae99015b615c5f2bf7",
              "lessThan": "0eede1689610e9eeaf729ba86fd1321799eb91a0",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "8d2ca1d7b5c3e63b3a8a81ae99015b615c5f2bf7",
              "lessThan": "b89b691dd00bf39b9ba39ab9446f8c62f419fa7b",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "8d2ca1d7b5c3e63b3a8a81ae99015b615c5f2bf7",
              "lessThan": "4553cfafa8d05c4ce20b1d18f79d9bb3b303fc02",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "8d2ca1d7b5c3e63b3a8a81ae99015b615c5f2bf7",
              "lessThan": "19b4ed644d68098cc62ab612727f40d30f43476c",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "net/ipv6/ip6_fib.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "3.13",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "3.13",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.10.271",
              "lessThanOrEqual": "5.10.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.15.222",
              "lessThanOrEqual": "5.15.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.189",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.158",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.111",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.53",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.7",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "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/05b687ee04f816658f4a9cf586f4d2f129157943",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/0eede1689610e9eeaf729ba86fd1321799eb91a0",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/14fdaba201fdff92a3e45994e02bccda409cb19d",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/19b4ed644d68098cc62ab612727f40d30f43476c",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/4553cfafa8d05c4ce20b1d18f79d9bb3b303fc02",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/63407cddabc5992b5ac03af165559f4a1968a032",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/9a3f73d62c86271614eda4c43315230896a37018",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/b89b691dd00bf39b9ba39ab9446f8c62f419fa7b",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}