Critical severity · published Apr 24, 2026
CVE-2026-31668
seg6: separate dst_cache for input and output paths in seg6 lwtunnel
9.8
CVSS
0.4%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 38% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
KE
Kernel · Linux
4.10.1 before 5.10.253; 5.11 before 5.15.203; 5.16 before 6.1.169; 6.2 before 6.6.135; 6.7 before 6.12.82; 6.13 before 6.18.23; +9 more · source: NVD
LI
Linux · Linux
6c8702c60b88651072460f3f4026c7dfe2521d12 before 1dec91d3b1cefb82635761b7812154af3ef46449; 6c8702c60b88651072460f3f4026c7dfe2521d12 before 750569d6987a0ff46317a4b86eb3907e296287bf; 6c8702c60b88651072460f3f4026c7dfe2521d12 before 57d0374d14fa667dec6952173b93e7e84486d5c9; 6c8702c60b88651072460f3f4026c7dfe2521d12 before 84d458018b147176b259347103fccb7e93abd2b1; 6c8702c60b88651072460f3f4026c7dfe2521d12 before 6305ad032b03d2ea4181b953a66e19a9a6ed053c; 6c8702c60b88651072460f3f4026c7dfe2521d12 before fb56de5d99218de49d5d43ef3a99e062ecd0f9a1; +3 more · source: vendor