Search: CVE-2026-31789

A heap buffer overflow vulnerability exists in OpenSSL on 32-bit platforms during hexadecimal conversion of large OCTET STRING values in X.509 certificates. This is caused by integer overflow in buffer size calculation when processing crafted certificates with large extensions like Subject Key Identifier or Authority Key Identifier. Exploitation could cause crashes or potentially allow attacker-controlled code execution, but requires certificates larger than 1 GB, making exploitation unlikely. The vulnerability does not affect OpenSSL FIPS modules. Fixes are available in updated OpenSSL packages for Ubuntu releases.