NULL pointer dereference in OpenSSL - CVE-2026-28389
Published: April 9, 2026
Vulnerability identifier: #VU125566
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-2026-28389
CWE-ID: CWE-476
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 NULL pointer dereference in CMS KeyAgreeRecipientInfo processing when processing a crafted CMS EnvelopedData message with a missing optional parameters field. A remote attacker can send a crafted CMS message to cause a denial of service.
Applications and services that call CMS_decrypt() on untrusted input, such as S/MIME processing or CMS-based protocols, are affected.
How to mitigate CVE-2026-28389
Install security update from vendor's website.