#VU125568 Heap-based buffer overflow in OpenSSL - CVE-2026-31789
Published: April 9, 2026
OpenSSL
OpenSSL Software Foundation
Description
The vulnerability allows a remote attacker to execute arbitrary code.
The vulnerability exists due to heap-based buffer overflow in hexadecimal conversion when converting an excessively large OCTET STRING value from an untrusted X.509 certificate to a hexadecimal string on 32-bit platforms. A remote attacker can supply a crafted X.509 certificate to execute arbitrary code.
Only 32-bit platforms are affected, and exploitation requires printing or logging untrusted X.509 certificates containing an OCTET STRING value larger than 1 gigabyte.