CVE-2026-79590

A NULL pointer dereference vulnerability exists in the Prism parser component of mruby 4.0.0. An attacker can provide a specially crafted Ruby source file that triggers the parser to pass a NULL pointer to nonnull string handling functions, resulting in undefined behavior and application crash.

• Published Sep 10, 2026
• CVSS 6.5 medium
• 0.4% chance of exploitation in the next 30 days (EPSS)
• A fix is available

CVE-2026-79590 at the National Vulnerability Database