CRITICAL: CVE-2026-31685 (CVSS 9.4) — multiple products

CVE: CVE-2026-31685

CVSS: 9.4 (3.1) — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:H

Severity: CRITICAL

Status: Critical advisory

Affected

_See vendor advisory_

Summary

In the Linux kernel, the following vulnerability has been resolved:

netfilter: ip6t_eui64: reject invalid MAC header for all packets

eui64_mt6() derives a modified EUI-64 from the Ethernet source address

and compares it with the low 64 bits of the IPv6 source address.

The existing guard only rejects an invalid MAC header when

par->fragoff != 0. For packets with par->fragoff == 0, eui64_mt6()

can still reach eth_hdr(skb) even when the MAC header is not valid.

Fix this by removing the par->fragoff != 0 condition so that packets

with an invalid MAC header are rejected before accessing eth_hdr(skb).

Verified Sources

References

https://git.kernel.org/stable/c/288138418bef956f8b295751a4536c60f0e89f4a
https://git.kernel.org/stable/c/309ae3e9a51a69699ca94eac5fac5688fa562d55
https://git.kernel.org/stable/c/807d6ee15804df6f01a35c910f09612e858739a6
https://git.kernel.org/stable/c/9eda5478746ef7dc0e4e537b5a5e4b0ca1027091
https://git.kernel.org/stable/c/fdce0b3590f724540795b874b4c8850c90e6b0a8

_Validated by the Lyrie Threat Intelligence Pipeline — 3 independent sources confirmed before publication. No speculation._

Lyrie Verdict

A vulnerability of this severity is exactly what Lyrie's anti-rogue-AI defense is built for: continuous, autonomous monitoring that doesn't wait for human reaction time.

#critical