What’s Vulnerable › Vulnerabilities

CVE-2026-80996: net: l2tp: do not propagate multicast notification errors

• Severity: unknown
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-11 · updated 2026-10-30

Description

In the Linux kernel, the following vulnerability has been resolved: net: l2tp: do not propagate multicast notification errors The tunnel create, tunnel modify, session create, and session modify netlink handlers send multicast notifications through helpers that can fail while allocating or encoding a message, or while multicasting it. For tunnel and session create/modify, a notification is sent after the live operation has completed. Returning a best-effort notification error as the command result can therefore report failure for an operation that already committed and can cause callers to retry and accumulate live objects. Keep sending notifications for listener visibility, but do not propagate their best-effort status as the command result. This also keeps the tunnel modify command consistent with the other notification-only paths.

Affected products

• Linux: 4.0 — fixed in 7.3

How to fix

Upgrade to a fixed version: Linux 7.3. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/0fe037d5eaad938aa3e9143ee071aa237750b42b
• https://git.kernel.org/stable/c/50c4038f1670bf9a80c6a58ae83d1602decd8481
• https://git.kernel.org/stable/c/73761c3cfb6d86392d63335d10f464b9d43275a7
• https://git.kernel.org/stable/c/7efe1c31e0903a5aa796feb96d3adab574b7ff41
• https://git.kernel.org/stable/c/9c340473f4822bb31b151c19afd17448eda5acd1
• https://git.kernel.org/stable/c/af20e269f7459d2ce69887fdf2fad7caf986c865

Get alerted when CVE-2026-80996 or the next vulnerability affects your stack