CVE-2026-31685 — CRITICAL (9.4)

Q: How severe is CVE-2026-31685?

CVE-2026-31685 has been rated CRITICAL with a CVSS base score of 9.4/10. This is considered a critical vulnerability requiring immediate attention.

Q: Is there a patch for CVE-2026-31685?

Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel.

Vulnerability Description

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 Score

9.4

CRITICAL

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

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

HIGH

Integrity

LOW

Availability

HIGH

Affected Products

Vendor	Product	Versions
Linux	Linux Kernel	>= 2.6.12.1, < 6.6.136

References

FAQ

What is CVE-2026-31685?

CVE-2026-31685 is a vulnerability with a CVSS score of 9.4 (CRITICAL). 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 ...

How severe is CVE-2026-31685?

CVE-2026-31685 has been rated CRITICAL with a CVSS base score of 9.4/10. This is considered a critical vulnerability requiring immediate attention.

Is there a patch for CVE-2026-31685?

Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel.