CVE-2026-31685

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

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

EPSS

0.5% chance of exploitation in the next 30 days; higher than 41% of CVEs (scores of 2026-10-25)

CWE

CWE-125

Published

2026-04-25

Modified

2026-10-19

Record from

the NVD, synced 2026-10-21

Affected

• linux:linux_kernel

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

Check your stackJSON