CVE-2026-31668

Critical

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.

SeverityCritical
CVSS9.8
Exploit probability—
ProductLinux Kernel
PublishedApr 24, 2026
First seenApr 24, 2026
Weakness typeCWE-459CWE-459

How to fix

Update
  • linux linux_kernel5.10.253, 5.15.203, 6.1.169, 6.6.135, 6.12.82, 6.18.23, 6.19.13 or later

Affected products

ProductAffected versionsFixed in
linux linux_kernel4.10.1 ≤ v < 5.10.253, 5.11 ≤ v < 5.15.203, 5.16 ≤ v < 6.1.169, 6.2 ≤ v < 6.6.135, 6.7 ≤ v < 6.12.82, 6.13 ≤ v < 6.18.23, 6.19 ≤ v < 6.19.13, 4.10, 7.05.10.253, 5.15.203, 6.1.169, 6.6.135, 6.12.82, 6.18.23, 6.19.13

Check your version

Choose the product and enter the version you run to see whether it falls in the affected range.

In the Intelligence 360 plan

Attack Surface Management

See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.