CVE-2026-31685critical

netfilter: ip6t_eui64: reject invalid MAC header for all packets

28Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 9.4epss 0.3%

exploitation probability

0.3%top 74% of all CVEs

observed exploitation

nono source reports it

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)`.

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

Affected products

Linux · Linux

References

https://git.kernel.org/stable/c/288138418bef956f8b295751a4536c60f0e89f4a https://git.kernel.org/stable/c/309ae3e9a51a69699ca94eac5fac5688fa562d55 https://git.kernel.org/stable/c/4d75bc2cd093bf5803edf512c099bfb220fd6459 https://git.kernel.org/stable/c/7d6a57411caf54df025860c9b1a82cd42d57a562 https://git.kernel.org/stable/c/807d6ee15804df6f01a35c910f09612e858739a6 https://git.kernel.org/stable/c/9eda5478746ef7dc0e4e537b5a5e4b0ca1027091 https://git.kernel.org/stable/c/d5603591373441fecf9951833d6d873e09320f08 https://git.kernel.org/stable/c/fdce0b3590f724540795b874b4c8850c90e6b0a8