Off-by-one in Linux kernel - CVE-2026-52921
Published: June 25, 2026
Vulnerability identifier: #VU135449
CSH Severity: Low
CVSS v4.0: 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
CVE-ID: CVE-2026-52921
CWE-ID: CWE-193
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
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.
How to mitigate CVE-2026-52921
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/02f75f041a93ea045834da89cd3234f4c1d749b4
- https://git.kernel.org/stable/c/0b530efb2cc9dbdddfd49d392e3a857f0d4ce8dc
- https://git.kernel.org/stable/c/0d3a282ab5f165fc207ff49ea5b6ad8f54616bd6
- https://git.kernel.org/stable/c/0d7b33ace701fe397e6e4de145f32e098178d901
- https://git.kernel.org/stable/c/383418c20e69f5761b6ec5238f599423f4fb77fb
- https://git.kernel.org/stable/c/952e988163c2ab9939c3db9f0f8e77af6a1bb436
- https://git.kernel.org/stable/c/be75218fadea22e59c8673db212f29c681bf45bb
- https://git.kernel.org/stable/c/c281e018af98df91827d65bec00f4956c00a1b02