seg6: separate dst_cache for input and output paths in seg6 lwtunnel
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.
- Products
- Kernel
- Affected versions
- Not specified
- Fixed versions
- 5.10.253, 5.15.203, 6.1.169, 6.12.82, 6.18.23, 6.19.13, 6.6.135
- CVEs
- CVE-2026-31668
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 7 Nov 2026, 01:48 UTC · Revision 1
Source evidence
seg6: separate dst_cache for input and output paths in seg6 lwtunnel
core-osv · Original sourcePublished 24 Apr 2026, 14:45 UTC
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.
osv:CVE-2026-31668
Kernel
Fixed versions: 5.10.253, 5.15.203, 6.1.169, 6.6.135, 6.12.82, 6.18.23, 6.19.13
Complete source record
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"id": "4546bff99e96f1118bea094c89eb7e0eecbdcdbc6e48abbf6e2936fb67b167d6",
"url": "https://osv.dev/vulnerability/CVE-2026-31668",
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"title": "seg6: separate dst_cache for input and output paths in seg6 lwtunnel",
"summary": "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.",
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"modified": "2026-10-28T02:30:48.680957345Z",
"provider": "osv",
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"https://nvd.nist.gov/vuln/detail/CVE-2026-31668",
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"source_id": "core-osv",
"document_id": 517107,
"published_at": "2026-04-24T14:45:16.63+00:00"
}