SB2026042548 - Improper access control in Linux kernel ipv6

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Main Vulnerability Database SB2026042548

SB2026042548 - Improper access control in Linux kernel ipv6

Published: April 25, 2026

Security Bulletin ID SB2026042548
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Data manipulation

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Improper access control (CVE-ID: CVE-2026-31668)

CWE-ID: CWE-284 - Improper Access Control

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a local user to bypass routing policy restrictions.

The vulnerability exists due to improper access control in the seg6 lwtunnel dst_cache handling when processing input and output paths in different routing contexts. A local user can trigger packet processing through one path so that the other path reuses an incorrect cached destination to bypass routing policy restrictions.

The issue occurs because a single destination cache is shared between seg6_input_core() and seg6_output_core(), even though these paths may perform SID lookup under different routing contexts such as ingress-interface-based rules or VRF table separation.


Remediation

Install update from vendor's website.

References