CVE-2026-98531ipv6: sr: enforce exact attribute length for SEG6_ATTR_DST
- —Not scoredno CVSS score yet
- 0.22%Exploitation in 30 daysEPSS · top 87% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: ipv6: sr: enforce exact attribute length for SEG6_ATTR_DST In seg6_genl_policy, SEG6_ATTR_DST is defined with .type = NLA_BINARY and .len = sizeof(struct in6_addr). For NLA_BINARY, .len only enforces the maximum payload length and permits shorter payloads (e.g., 0 bytes). When seg6_genl_set_tunsrc() copies sizeof(struct in6_addr) bytes via kmemdup(val, sizeof(*val), GFP_KERNEL), a short SEG6_ATTR_DST attribute triggers a 16-byte out-of-bounds read past skb->tail into uninitialized skb->head memory, which is stored in sdata->tun_src and leaked back to userspace via SEG6_CMD_GET_TUNSRC. Switch SEG6_ATTR_DST in seg6_genl_policy to NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)) so that generic netlink validation rejects any attribute whose length is not exactly sizeof(struct in6_addr) with -ERANGE. Tested in QEMU against Linux 7.3.0-rc3 by sending a SEG6_CMD_SET_TUNSRC Generic Netlink message with a 0-byte SEG6_ATTR_DST attribute followed by SEG6_CMD_GET_TUNSRC. On the unfixed kernel, SEG6_CMD_SET_TUNSRC succeeds (err = 0) and SEG6_CMD_GET_TUNSRC leaks 16 bytes of uninitialized kernel heap memory (tun_src = 836a61ecc4d25a1042a8d60411cfb378); with this patch applied, SEG6_CMD_SET_TUNSRC is rejected by netlink policy validation with -ERANGE (-34) and tun_src remains zeroed.
Timeline
ID reserved
By Linux
- 23 days later
· 23 days later
Published
- 1 day later
· 1 day later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
No CVSS score yet: neither the CNA, CISA nor NVD has scored this CVE. NVD status: Received.
- EPSS (exploitation in 30 days)
- 0.22% · top 87% of all CVEs (12 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Not scored.
Affected products
- affected 915d7e5e5930b4f01d0971d93b9b25ed17d221aa – < 050a0aa3c80907b8c60a396b7e04d48d8b1a9e70
- affected 915d7e5e5930b4f01d0971d93b9b25ed17d221aa – < 209eefebee54c4a5f01d68b61e8ac9881eca2de9
- affected 915d7e5e5930b4f01d0971d93b9b25ed17d221aa – < e3ac68c1cdc2535d127b2bfd50c263d16c8e4199
- affected 915d7e5e5930b4f01d0971d93b9b25ed17d221aa – < 66bf65fa109326e4c4ddeb0b94093379f72838fd
- affected 915d7e5e5930b4f01d0971d93b9b25ed17d221aa – < 195813bb7324c338eaba0aaa02b18681ee65b670
- affected 915d7e5e5930b4f01d0971d93b9b25ed17d221aa – < 6fcfc362344edea745a69f3a705de50b731f3418
- affected 915d7e5e5930b4f01d0971d93b9b25ed17d221aa – < 94214cf0a08dd2c5f37aeeea46078d9dfe8e4a0e
- affected 915d7e5e5930b4f01d0971d93b9b25ed17d221aa – < 2d959c75c27f90e9ec489d18ce5ee6b852ad4741
- affected 4.10
- unaffected < 4.10
- unaffected 5.10.271 – ≤ 5.10.*
- unaffected 5.15.222 – ≤ 5.15.*
- unaffected 6.1.189 – ≤ 6.1.*
- unaffected 6.6.158 – ≤ 6.6.*
- unaffected 6.12.112 – ≤ 6.12.*
- unaffected 6.18.55 – ≤ 6.18.*
- unaffected 7.2.9 – ≤ 7.2.*
- unaffected 7.3 – ≤ *
References
References8
- https://git.kernel.org/stable/c/050a0aa3c80907b8c60a396b7e04d48d8b1a9e70 (opens in a new tab)
- https://git.kernel.org/stable/c/209eefebee54c4a5f01d68b61e8ac9881eca2de9 (opens in a new tab)
- https://git.kernel.org/stable/c/e3ac68c1cdc2535d127b2bfd50c263d16c8e4199 (opens in a new tab)
- https://git.kernel.org/stable/c/66bf65fa109326e4c4ddeb0b94093379f72838fd (opens in a new tab)
- https://git.kernel.org/stable/c/195813bb7324c338eaba0aaa02b18681ee65b670 (opens in a new tab)
- https://git.kernel.org/stable/c/6fcfc362344edea745a69f3a705de50b731f3418 (opens in a new tab)
- https://git.kernel.org/stable/c/94214cf0a08dd2c5f37aeeea46078d9dfe8e4a0e (opens in a new tab)
- https://git.kernel.org/stable/c/2d959c75c27f90e9ec489d18ce5ee6b852ad4741 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-103576 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-98531)Record last updated .