NULL pointer dereference in OpenSSL - CVE-2026-75805
Published: September 30, 2026
Vulnerability identifier: #VU152961
CSH Severity: Low
CVSS v4: 6 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-75805
CWE-ID: CWE-476
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to a NULL pointer dereference in CMP client revocation response handling when processing a crafted response to a revocation request based on a PKCS#10 CSR. A remote user can send a crafted revocation response to cause a denial of service.
The response must pass message-protection validation, and clients identifying the certificate by a certificate or issuer and serial number are not affected.
Affected software
OpenSSL
Debian Linux
openssl (Debian package)
Debian Linux
openssl (Debian package)
How to mitigate CVE-2026-75805
Install security update from vendor's website.
OpenSSL - addressed in versions 1.0.2zs, 1.1.1zj, 3.0.23, 3.4.8, 3.5.9, 3.6.5, 4.0.3
openssl (Debian package) - update to 3.5.7-1~deb13u3
openssl (Debian package) - update to 3.5.7-1~deb13u3