SB20260625259 - Improper locking in Linux kernel crypto
Published: June 25, 2026
Security Bulletin ID
SB20260625259
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Improper locking (CVE-ID: CVE-2026-52936)
CWE-ID: CWE-667 - Improper Locking
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 improper lock management in jent_kcapi_random() when generating entropy for parallel readers. A local user can trigger concurrent requests to cause a denial of service.
The issue arises because a shared lock is held across expensive entropy collection and SHA3 conditioning operations, causing contending readers to spin and stall.
Remediation
Install update from vendor's website.
References
- https://git.kernel.org/stable/c/01d798e9feb30212952d4e992801ba6bd6a82351
- https://git.kernel.org/stable/c/18216b8ab6904753eaf31baf453cb02ecd202ba4
- https://git.kernel.org/stable/c/4c03e6eb98443dc4d6d422a9780034a5b75376b4
- https://git.kernel.org/stable/c/ec427dc5286da1ed08f2d510e2147a7581b0cb02
- https://git.kernel.org/stable/c/ff734dbd9e2432601a6dcd167cfb0bf8a36d1880