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.

No CVSS v4.0

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
Linux Linux unaffected
Version Status Constraints
6c8702c60b88651072460f3f4026c7dfe2521d12 affected < 1dec91d3b1cefb82635761b7812154af3ef46449
6c8702c60b88651072460f3f4026c7dfe2521d12 affected < 750569d6987a0ff46317a4b86eb3907e296287bf
6c8702c60b88651072460f3f4026c7dfe2521d12 affected < 57d0374d14fa667dec6952173b93e7e84486d5c9
6c8702c60b88651072460f3f4026c7dfe2521d12 affected < 84d458018b147176b259347103fccb7e93abd2b1
6c8702c60b88651072460f3f4026c7dfe2521d12 affected < 6305ad032b03d2ea4181b953a66e19a9a6ed053c
6c8702c60b88651072460f3f4026c7dfe2521d12 affected < fb56de5d99218de49d5d43ef3a99e062ecd0f9a1
6c8702c60b88651072460f3f4026c7dfe2521d12 affected < 17d87d42874f5d6c1a0ccc6d9190dfe82a9a7a6a
6c8702c60b88651072460f3f4026c7dfe2521d12 affected < c3812651b522fe8437ebb7063b75ddb95b571643
Linux Linux affected
Version Status Constraints
4.10 affected —
0 unaffected < 4.10
5.10.253 unaffected ≤ 5.10.*
5.15.203 unaffected ≤ 5.15.*
6.1.169 unaffected ≤ 6.1.*
6.6.135 unaffected ≤ 6.6.*
6.12.82 unaffected ≤ 6.12.*
6.18.23 unaffected ≤ 6.18.*
6.19.13 unaffected ≤ 6.19.*
7.0 unaffected ≤ *

No data.

No data.

No data.

Project Subscriptions

Vendors Products
Linux Subscribe
Linux Kernel Subscribe
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://git.kernel.org/stable/c/17d87d42874f5d6c1a0ccc6d9190dfe82a9a7a6a cve-icon cve-icon
https://git.kernel.org/stable/c/1dec91d3b1cefb82635761b7812154af3ef46449 cve-icon cve-icon
https://git.kernel.org/stable/c/57d0374d14fa667dec6952173b93e7e84486d5c9 cve-icon cve-icon
https://git.kernel.org/stable/c/6305ad032b03d2ea4181b953a66e19a9a6ed053c cve-icon cve-icon
https://git.kernel.org/stable/c/750569d6987a0ff46317a4b86eb3907e296287bf cve-icon cve-icon
https://git.kernel.org/stable/c/84d458018b147176b259347103fccb7e93abd2b1 cve-icon cve-icon
https://git.kernel.org/stable/c/c3812651b522fe8437ebb7063b75ddb95b571643 cve-icon cve-icon
https://git.kernel.org/stable/c/fb56de5d99218de49d5d43ef3a99e062ecd0f9a1 cve-icon cve-icon
https://lore.kernel.org/linux-cve-announce/2026042406-CVE-2026-31668-50e7@gregkh/T cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2026-31668 cve-icon
https://www.cve.org/CVERecord?id=CVE-2026-31668 cve-icon
History

Sat, 25 Apr 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-821
References
Metrics threat_severity

None

 cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate

Fri, 24 Apr 2026 15:00:00 +0000

Type Values Removed Values Added
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.
Title seg6: separate dst_cache for input and output paths in seg6 lwtunnel
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-04-24T14:45:16.630Z

Reserved: 2026-03-09T15:48:24.129Z

Link: CVE-2026-31668

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-04-24T15:16:46.533

Modified: 2026-04-24T17:51:40.810

Link: CVE-2026-31668

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-04-24T00:00:00Z

Links: CVE-2026-31668 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses