SB20261022216 - Out-of-bounds read in Linux kernel xdp



SB20261022216 - Out-of-bounds read in Linux kernel xdp

Published: October 22, 2026

Security Bulletin ID SB20261022216
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Information disclosure

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Out-of-bounds read (CVE-ID: CVE-2026-98631)

CWE-ID: CWE-125 - Out-of-bounds read

CVSSv4: 2 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a local user to read out-of-bounds kernel memory, potentially disclosing sensitive information.

The vulnerability exists due to an out-of-bounds read in the Linux kernel's xsk_map_gen_lookup() function when generated lookup code compares a zero-extended 32-bit key against a sign-extended 64-bit bound. A local user can supply an out-of-range lookup key that bypasses the bounds check to read beyond the xsk_map[] array.

Exploitation requires a map with max_entries set to 0x80000000 or higher.


Remediation

Install update from vendor's website.