CVE-2026-31668

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.

CVSS 3.1

9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

0.4% chance of exploitation in the next 30 days; higher than 38% of CVEs (scores of 2026-10-25)

CWE

CWE-459

Published

2026-04-24

Modified

2026-10-19

Record from

the NVD, synced 2026-10-21

Affected

• linux:linux_kernel

References

• https://git.kernel.org/stable/c/17d87d42874f5d6c1a0ccc6d9190dfe82a9a7a6a
• https://git.kernel.org/stable/c/1dec91d3b1cefb82635761b7812154af3ef46449
• https://git.kernel.org/stable/c/57d0374d14fa667dec6952173b93e7e84486d5c9
• https://git.kernel.org/stable/c/6305ad032b03d2ea4181b953a66e19a9a6ed053c
• https://git.kernel.org/stable/c/750569d6987a0ff46317a4b86eb3907e296287bf

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