{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "915d7e5e5930b4f01d0971d93b9b25ed17d221aa"
            },
            {
              "fixed": "050a0aa3c80907b8c60a396b7e04d48d8b1a9e70"
            },
            {
              "fixed": "209eefebee54c4a5f01d68b61e8ac9881eca2de9"
            },
            {
              "fixed": "e3ac68c1cdc2535d127b2bfd50c263d16c8e4199"
            },
            {
              "fixed": "66bf65fa109326e4c4ddeb0b94093379f72838fd"
            },
            {
              "fixed": "195813bb7324c338eaba0aaa02b18681ee65b670"
            },
            {
              "fixed": "6fcfc362344edea745a69f3a705de50b731f3418"
            },
            {
              "fixed": "94214cf0a08dd2c5f37aeeea46078d9dfe8e4a0e"
            },
            {
              "fixed": "2d959c75c27f90e9ec489d18ce5ee6b852ad4741"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.10.0"
            },
            {
              "fixed": "5.10.271"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.11.0"
            },
            {
              "fixed": "5.15.222"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.189"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.158"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.112"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.55"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.9"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98531.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: sr: enforce exact attribute length for SEG6_ATTR_DST\n\nIn seg6_genl_policy, SEG6_ATTR_DST is defined with .type = NLA_BINARY and\n.len = sizeof(struct in6_addr). For NLA_BINARY, .len only enforces the\nmaximum payload length and permits shorter payloads (e.g., 0 bytes).\nWhen seg6_genl_set_tunsrc() copies sizeof(struct in6_addr) bytes via\nkmemdup(val, sizeof(*val), GFP_KERNEL), a short SEG6_ATTR_DST attribute\ntriggers a 16-byte out-of-bounds read past skb-\u003etail into uninitialized\nskb-\u003ehead memory, which is stored in sdata-\u003etun_src and leaked back to\nuserspace via SEG6_CMD_GET_TUNSRC.\n\nSwitch SEG6_ATTR_DST in seg6_genl_policy to\nNLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)) so that generic netlink\nvalidation rejects any attribute whose length is not exactly\nsizeof(struct in6_addr) with -ERANGE.\n\nTested in QEMU against Linux 7.3.0-rc3 by sending a SEG6_CMD_SET_TUNSRC\nGeneric Netlink message with a 0-byte SEG6_ATTR_DST attribute followed\nby SEG6_CMD_GET_TUNSRC. On the unfixed kernel, SEG6_CMD_SET_TUNSRC\nsucceeds (err = 0) and SEG6_CMD_GET_TUNSRC leaks 16 bytes of\nuninitialized kernel heap memory (tun_src =\n836a61ecc4d25a1042a8d60411cfb378); with this patch applied,\nSEG6_CMD_SET_TUNSRC is rejected by netlink policy validation with\n-ERANGE (-34) and tun_src remains zeroed.",
  "id": "CVE-2026-98531",
  "modified": "2026-10-19T02:30:44.433049947Z",
  "published": "2026-10-18T15:17:49.632Z",
  "references": [
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/050a0aa3c80907b8c60a396b7e04d48d8b1a9e70"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/195813bb7324c338eaba0aaa02b18681ee65b670"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/209eefebee54c4a5f01d68b61e8ac9881eca2de9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2d959c75c27f90e9ec489d18ce5ee6b852ad4741"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/66bf65fa109326e4c4ddeb0b94093379f72838fd"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6fcfc362344edea745a69f3a705de50b731f3418"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/94214cf0a08dd2c5f37aeeea46078d9dfe8e4a0e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e3ac68c1cdc2535d127b2bfd50c263d16c8e4199"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98531.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98531"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "ipv6: sr: enforce exact attribute length for SEG6_ATTR_DST"
}