Vulnerability · Published Sep 10, 2026 · Assigned by mitre
CVE-2026-79590
Medium 6.5
In plain English
A medium-severity null pointer dereference in the mruby package (Debian). Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 31% of all known vulnerabilities).
Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)0.4%top 69.3% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | mruby | no fix listed | DEBIAN-CVE-2026-79590 |
| Debian:13 | mruby | no fix listed | DEBIAN-CVE-2026-79590 |
| Debian:14 | mruby | no fix listed | DEBIAN-CVE-2026-79590 |
| Ubuntu:22.04:LTS | mruby | no fix listed | UBUNTU-CVE-2026-79590 |
| Ubuntu:24.04:LTS | mruby | no fix listed | UBUNTU-CVE-2026-79590 |
| Ubuntu:26.04:LTS | mruby | no fix listed | UBUNTU-CVE-2026-79590 |
| Ubuntu:26.10 | mruby | no fix listed | UBUNTU-CVE-2026-79590 |
Affected products (as reported)
Weakness: CWE-476 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H