SB20260625261 - Off-by-one in Linux kernel netfilter ipset



SB20260625261 - Off-by-one in Linux kernel netfilter ipset

Published: June 25, 2026

Security Bulletin ID SB20260625261
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Denial of service

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Off-by-one (CVE-ID: CVE-2026-52921)

CWE-ID: CWE-193 - Off-by-one Error

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


The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to an off-by-one error in the netfilter ipset hash set range iteration logic when processing IPv4 ranges in hash:ip,mark, hash:ip,port, hash:ip,port,ip, and hash:ip,port,net set variants. A local user can supply a crafted range request to cause a denial of service.

A later retry may continue from an unintended position after traversal advances past the end of the requested range.


Remediation

Install update from vendor's website.