Out-of-bounds read in OpenSSL - CVE-2026-28386
Published: April 9, 2026
Vulnerability identifier: #VU125563
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-28386
CWE-ID: CWE-125
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: OpenSSL Software Foundation
Affected software:
OpenSSL
OpenSSL
Detailed vulnerability description
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to out-of-bounds read in AES-CFB-128 processing when handling partial cipher blocks on x86-64 systems with AVX-512 and VAES support. A local user can trigger processing of crafted input at a page boundary to cause a denial of service.
Only x86-64 systems with AVX-512 and VAES support are affected, and the issue is reached only when processing partial blocks with the following memory page unmapped.
How to mitigate CVE-2026-28386
Install security update from vendor's website.