SB20260626129 - Use of Uninitialized Variable in Linux kernel bridge netfilter

Description

This security bulletin contains information about 1 vulnerability.

1) Use of Uninitialized Variable (CVE-ID: CVE-2026-53211)

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

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/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 an uninitialized memory exposure in nft_meta_bridge_get_eval() when handling NFT_META_BRI_IIFHWADDR register data. A local user can trigger a downstream load of the affected register span to disclose sensitive information.

The issue occurs because only 6 bytes are copied into a declared 8-byte destination register span, leaving 2 bytes of stale stack data available to userspace.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/07acb9798477535933bd658ac9fa85b6cb10d995
• https://git.kernel.org/stable/c/c7d573551f9286100a055ef696cde6af54549677
• https://git.kernel.org/stable/c/f1e81d571e375d10e50e852223593493d98c1bac