CVE-2025-21768: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: net: ipv6: fix dst ref loops in rpl, seg6 and ioam6 lwtunnels Some lwtunnels have a dst cache for post-transformation dst. If the packet destination did not change we may end up recording a reference to the lwtunnel in its own cache, and the lwtunnel state will never be freed. Discovered by the ioam6.sh test, kmemleak was recently fixed to catch per-cpu memory leaks. I'm not sure if rpl and seg6 can actually hit this, but in principle I don't see why not.

Affected products

• Linux Linux Kernel: from 4.10, before 6.12.16 (fixed in 6.12.16); from 6.13, before 6.13.4 (fixed in 6.13.4); version 6.14 only

Published 2025-02-27. Last modified 2026-06-17.