Out-of-bounds read in OpenSSL - CVE-2026-9076
Published: June 10, 2026
Vulnerability identifier: #VU134277
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-9076
CWE-ID: CWE-125
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: OpenSSL Software Foundation
Affected software:
OpenSSL
OpenSSL
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to out-of-bounds read in kek_unwrap_key() when processing attacker-supplied CMS password-based decryption data with a stream-mode KEK cipher. A remote attacker can send a specially crafted CMS message to cause a denial of service.
No password knowledge is required because the over-read occurs during the unwrap attempt before authentication succeeds.
How to mitigate CVE-2026-9076
Install security update from vendor's website.