{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "764dd163ac922f8683b5bcd3007251ce7b26cd33"
            },
            {
              "fixed": "8c10778ec674b67a07ea042fcba64270f3f38a5a"
            },
            {
              "fixed": "2731efa6364e47934c96eb69e01ea131e8af8030"
            },
            {
              "fixed": "00c06ef8c018493943891a7d0ca82b71b24f3180"
            },
            {
              "fixed": "c141f69d0a0fb16964dbc293650047e69bda8af7"
            },
            {
              "fixed": "f2e6596d10783557aeb9668da2a3b4d19deb2001"
            },
            {
              "fixed": "1c4f67c89fd27c4df4c70b135c2c59627698b3c0"
            },
            {
              "fixed": "4ac981a8b7ce7aec99a52d08f8a8953e8e120067"
            },
            {
              "fixed": "86f3ce81dd2b4b0aa2c3016c989a943e4b1b643d"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.3.0"
            },
            {
              "fixed": "5.10.261"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.11.0"
            },
            {
              "fixed": "5.15.212"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.178"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.145"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.97"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.40"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64554.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: bridge: fix stale prevhdr pointer in br_ip6_fragment()\n\nbr_ip6_fragment() gets prevhdr, a pointer into the skb head, from\nip6_find_1stfragopt(), then calls skb_checksum_help().  For a cloned skb\nskb_checksum_help() reallocates the head via pskb_expand_head(), leaving\nprevhdr dangling.  It is later dereferenced in ip6_frag_next(), causing a\nuse-after-free write.\n\nSave prevhdr's offset before skb_checksum_help() and recompute it after,\nlike commit ef0efcd3bd3f (\"ipv6: Fix dangling pointer when ipv6\nfragment\").\n\n  BUG: KASAN: slab-use-after-free in ip6_frag_next (net/ipv6/ip6_output.c:857)\n  Write of size 1 at addr ffff888013ff5016 by task exploit/141\n  Call Trace:\n   ...\n   kasan_report (mm/kasan/report.c:595)\n   ip6_frag_next (net/ipv6/ip6_output.c:857)\n   br_ip6_fragment (net/ipv6/netfilter.c:212)\n   nf_ct_bridge_post (net/bridge/netfilter/nf_conntrack_bridge.c:407)\n   nf_hook_slow (net/netfilter/core.c:619)\n   br_forward_finish (net/bridge/br_forward.c:66)\n   __br_forward (net/bridge/br_forward.c:115)\n   maybe_deliver (net/bridge/br_forward.c:191)\n   br_flood (net/bridge/br_forward.c:245)\n   br_handle_frame_finish (net/bridge/br_input.c:229)\n   br_handle_frame (net/bridge/br_input.c:442)\n   ...\n   packet_sendmsg (net/packet/af_packet.c:3114)\n   ...\n   do_syscall_64 (arch/x86/entry/syscall_64.c:94)\n   entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)\n  Kernel panic - not syncing: Fatal exception in interrupt",
  "id": "CVE-2026-64554",
  "modified": "2026-08-18T03:31:24.922616638Z",
  "published": "2026-07-27T20:10:41.726Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/00c06ef8c018493943891a7d0ca82b71b24f3180"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1c4f67c89fd27c4df4c70b135c2c59627698b3c0"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2731efa6364e47934c96eb69e01ea131e8af8030"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4ac981a8b7ce7aec99a52d08f8a8953e8e120067"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/86f3ce81dd2b4b0aa2c3016c989a943e4b1b643d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8c10778ec674b67a07ea042fcba64270f3f38a5a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c141f69d0a0fb16964dbc293650047e69bda8af7"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f2e6596d10783557aeb9668da2a3b4d19deb2001"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64554.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64554"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "netfilter: bridge: fix stale prevhdr pointer in br_ip6_fragment()"
}