CVE-2026-97940: Linux kernel · ipv6: fix fib6 walker UAF on seq stop
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 25 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix has been implemented in the Linux kernel to address this vulnerability. Users should apply the official kernel updates that resolve this issue. Since this is a kernel-level vulnerability, upgrading to a patched kernel version is the recommended remediation. No additional mitigations are specified by the vendor advisory.
Description
A use-after-free vulnerability in the Linux kernel's IPv6 fib6 walker was resolved. The issue occurs when the fib6 walker is incorrectly treated as unlinked, leading to a freed object being accessed later during route deletion. This affects the /proc/net/ipv6_route and BPF IPv6 route iterators. The vulnerability has a CVSS score of 7.8, indicating high impact on confidentiality, integrity, and availability.
References
- ubuntu.com/security/CVE-2026-97940 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-97940 (opens in a new tab)
- git.kernel.org/stable/c/0eede1689610e9eeaf729ba86fd1321799eb91a0 (opens in a new tab)
- git.kernel.org/stable/c/19b4ed644d68098cc62ab612727f40d30f43476c (opens in a new tab)
- git.kernel.org/stable/c/4553cfafa8d05c4ce20b1d18f79d9bb3b303fc02 (opens in a new tab)
- git.kernel.org/stable/c/b89b691dd00bf39b9ba39ab9446f8c62f419fa7b (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-97940 (opens in a new tab)
- git.kernel.org/stable/c/05b687ee04f816658f4a9cf586f4d2f129157943 (opens in a new tab)
- git.kernel.org/stable/c/14fdaba201fdff92a3e45994e02bccda409cb19d (opens in a new tab)
- git.kernel.org/stable/c/63407cddabc5992b5ac03af165559f4a1968a032 (opens in a new tab)
- git.kernel.org/stable/c/9a3f73d62c86271614eda4c43315230896a37018 (opens in a new tab)