SB2026082170 - Incorrect Bitwise Shift of Integer in Linux kernel netfilter

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Main Vulnerability Database SB2026082170

SB2026082170 - Incorrect Bitwise Shift of Integer in Linux kernel netfilter

Published: August 21, 2026

Security Bulletin ID SB2026082170
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) Incorrect Bitwise Shift of Integer (CVE-ID: CVE-2026-74579)

CWE-ID: CWE-1335 - Incorrect Bitwise Shift of Integer

CVSSv4: 4.6 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a local privileged user to cause incorrect netfilter payload offload matching.

The vulnerability exists due to undefined shift behavior in nft_payload_offload_mask() in net/netfilter/nft_payload.c when building an offload match mask for a payload expression that covers only part of a header field. A local privileged user can configure a crafted nftables payload rule with a partial header field match to cause incorrect netfilter payload offload matching.

The issue occurs for partial field matches such as a partial IPv6 address match where the match length is shorter than the header field length.


Remediation

Install update from vendor's website.

References