SB20260626214 - Use of Uninitialized Variable in Linux kernel netfilter



SB20260626214 - Use of Uninitialized Variable in Linux kernel netfilter

Published: June 26, 2026

Security Bulletin ID SB20260626214
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) Use of Uninitialized Variable (CVE-ID: CVE-2026-53134)

CWE-ID: CWE-457 - Use of Uninitialized Variable

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


The vulnerability allows a local user to disclose sensitive information.

The vulnerability exists due to uninitialized memory exposure in the nft_fib IPv4/IPv6 evaluation logic when processing nftables fib expressions that use the OIFNAME result or an invalid NFTA_FIB_F_PRESENT combination. A local user can configure and trigger a crafted fib expression to disclose sensitive information.

The issue occurs because only part of the declared destination register span is written on certain evaluation paths, leaving stale kernel stack data available to a downstream expression that reads the full register span.


Remediation

Install update from vendor's website.