CVE-2026-34182
CVE-2026-34182 is a critical vulnerability in OpenSSL 4.0.0 where improper input validation in Cryptographic Message Services (CMS) processing allows attackers to compromise encryption keys or bypass message integrity checks by manipulating cipher/tag length fields.
No official fix yet. If none appears within 45 days of first tracking, this entry is removed automatically.
Who is affected
Users of OpenSSL 4.0.0
Real-world impact
Attackers could decrypt messages without valid keys or alter encrypted content without detection, potentially leading to data breaches or unauthorized actions.
Why this severity
CVSS 9.1 (critical) due to high confidence in remote exploitation without user interaction or privileges.
What to do about it
- ›Avoid using OpenSSL 4.0.0 until a patched version is available.
- ›Implement strict input validation for CMS operations if custom implementations are used.
No official fix or mitigation is documented in the sources yet. Monitor the vendor advisory and apply the patch as soon as it is released.
No fix documented in sources
Timeline
- Jun 9, 2026 · Jun 9, 2026PublishedDisclosed and added to the National Vulnerability Database.
- Jul 23, 2026 · 12d agoAdvisory updatedThe NVD record was last revised.