CVE-2026-31668

CRITICAL

seg6: separate dst_cache for input and output paths in seg6 lwtunnel

Title source: cna
STIX 2.1

Description

In the Linux kernel, the following vulnerability has been resolved: seg6: separate dst_cache for input and output paths in seg6 lwtunnel The seg6 lwtunnel uses a single dst_cache per encap route, shared between seg6_input_core() and seg6_output_core(). These two paths can perform the post-encap SID lookup in different routing contexts (e.g., ip rules matching on the ingress interface, or VRF table separation). Whichever path runs first populates the cache, and the other reuses it blindly, bypassing its own lookup. Fix this by splitting the cache into cache_input and cache_output, so each path maintains its own cached dst independently.

Scores

CVSS v3 9.8
EPSS 0.0044
EPSS Percentile 35.8%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Details

Status published
Products (28)
linux/Kernel 4.10.0 - 5.10.253linux
linux/Kernel 5.11.0 - 5.15.203linux
linux/Kernel 5.16.0 - 6.1.169linux
linux/Kernel 6.13.0 - 6.18.23linux
linux/Kernel 6.19.0 - 6.19.13linux
linux/Kernel 6.2.0 - 6.6.135linux
linux/Kernel 6.7.0 - 6.12.82linux
Linux/Linux < 4.10
Linux/Linux 4.10
Linux/Linux 5.10.253 - 5.10.*
... and 18 more
Published Apr 24, 2026
Tracked Since Apr 24, 2026