CVE-2026-31668 Details
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.
A vulnerability in the Linux kernel's Segment Routing (SR) implementation can lead to improper handling of destination caches in lightweight tunnels. This issue arises because the SR tunnels use a single destination cache for both input and output paths, which can create conflicts when the paths are processed in different routing contexts. As a result, one path may overwrite the cache used by the other, bypassing necessary routing lookups. The vulnerability affects the Linux kernel stable group.
The vulnerability has been addressed by modifying the Segment Routing lightweight tunnel implementation to use separate destination caches for input and output paths. Users should upgrade to the latest version of the Linux kernel where this fix has been applied.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
No SSVC data is available for this CVE.
References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://git.kernel.org/stable/c/17d87d42874f5d6c1a0ccc6d9190dfe82a9a7a6a | kernel.org | Patch |
| https://git.kernel.org/stable/c/1dec91d3b1cefb82635761b7812154af3ef46449 | kernel.org | Patch |
| https://git.kernel.org/stable/c/57d0374d14fa667dec6952173b93e7e84486d5c9 | kernel.org | Patch |
| https://git.kernel.org/stable/c/6305ad032b03d2ea4181b953a66e19a9a6ed053c | kernel.org | Patch |
| https://git.kernel.org/stable/c/750569d6987a0ff46317a4b86eb3907e296287bf | kernel.org | Patch |
| https://git.kernel.org/stable/c/84d458018b147176b259347103fccb7e93abd2b1 | kernel.org | Patch |
| https://git.kernel.org/stable/c/c3812651b522fe8437ebb7063b75ddb95b571643 | kernel.org | Patch |
| https://git.kernel.org/stable/c/fb56de5d99218de49d5d43ef3a99e062ecd0f9a1 | kernel.org | Patch |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| NVD-CWE-noinfo | Insufficient Information to Classify Weakness | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| linux linux kernel | >= 4.10.1, < 5.10.253 >= 5.11, < 5.15.203 >= 5.16, < 6.1.169 >= 6.2, < 6.6.135 >= 6.7, < 6.12.82 >= 6.13, < 6.18.23 >= 6.19, < 6.19.13 4.10 - 7.0 rc1 7.0 rc2 7.0 rc3 7.0 rc4 7.0 rc5 7.0 rc6 7.0 rc7 |
CPE
Remediation
| |
Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | kernel.org |
| Apr 27, 2026 | Initial Analysis | [email protected] |
| Apr 27, 2026 | CVE Modified | kernel.org |
| Apr 24, 2026 | New CVE Received | kernel.org |