CVE-2026-31668
Full vulnerability record from the local CVENow database.
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.
Severity
CRITICAL
CVSS score
9.8
(v3.1)
Vulnerability status
Modified
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-04-24 15:16:46.533000
Last modified
2026-10-19 19:18:04.760000
View original CVE JSON
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"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-04-24T15:16:46.533",
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"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nseg6: separate dst_cache for input and output paths in seg6 lwtunnel\n\nThe seg6 lwtunnel uses a single dst_cache per encap route, shared\nbetween seg6_input_core() and seg6_output_core(). These two paths\ncan perform the post-encap SID lookup in different routing contexts\n(e.g., ip rules matching on the ingress interface, or VRF table\nseparation). Whichever path runs first populates the cache, and the\nother reuses it blindly, bypassing its own lookup.\n\nFix this by splitting the cache into cache_input and cache_output,\nso each path maintains its own cached dst independently."
}
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