CVE-2025-12875: A weakness has been identified in mruby 3.4.0. This vulnerability affects the function ary_fill_exec of the file…
CVE-2025-12875 · Severity: medium · CVSS 5.3 · Published 2025-11-07
A weakness has been identified in mruby 3.4.0. This vulnerability affects the function ary_fill_exec of the file mrbgems/mruby-array-ext/src/array.c. Executing a manipulation of the argument start/length can lead to out-of-bounds write. The attack needs to be launched locally. The exploit has been made available to the public and could be used for attacks. This patch is called 93619f06dd378db6766666b30c08978311c7ec94. It is best practice to apply a patch to resolve this issue.
No. Junglewise Threat Intelligence has no report of CVE-2025-12875 being exploited in the wild.
How severe is CVE-2025-12875?
Medium severity, with a CVSS score of 5.3, published 7 November 2025.
Which products and versions are affected?
Mruby. The advisory does not name versions.
Is there a fix for CVE-2025-12875?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
Am I affected by CVE-2025-12875?
Check whether you run Mruby. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.