CVE-2026-31789
A vulnerability in OpenSSL allows for a heap buffer overflow when converting large data values within X.509 certificates into hexadecimal strings. This occurs specifically on 32-bit platforms when an excessively large value causes a calculation error during memory allocation.
No official fix yet. If none appears within 45 days of first tracking, this entry is removed automatically.
Who is affected
Users of OpenSSL on 32-bit platforms, specifically applications or services that print or log the contents of untrusted X.509 certificates.
Real-world impact
An attacker could potentially cause a system crash or execute arbitrary code by providing a specially crafted X.509 certificate containing an extremely large data field.
Why this severity
The critical score reflects that the vulnerability is remotely exploitable without user interaction or authentication, potentially leading to full system compromise.
What to do about it
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
- Apr 7, 2026 · Apr 7, 2026PublishedDisclosed and added to the National Vulnerability Database.
- Jul 24, 2026 · 11d agoAdvisory updatedThe NVD record was last revised.
How it’s attacked
References & advisories
- github.com/openssl/openssl/commit/364f…patch
- github.com/openssl/openssl/commit/7a90…patch
- github.com/openssl/openssl/commit/945b…patch
- github.com/openssl/openssl/commit/a242…patch
- github.com/openssl/openssl/commit/a91e…patch
- openssl-library.org/news/secadv/20260407.txtvendor advisory
- cert-portal.siemens.com/productcert/html/ssa-032379…