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CVE-2025-13120VulnerabilityPublished Updated

CVE-2025-13120: mruby · Use After Free

Affects mrubySource CVE Database V5

0

Not known to be exploited · CVSS 4.8 Medium.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 4.0 base score
4.8Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 13 Nov 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

What to do

Affected software

ProductAffectedFixed in
GitHubmruby/mrubypkg:github/mruby/mrubyOther threatsAffected
  • =3.0
  • =3.1
  • =3.2
  • =3.3
  • =3.4.0
Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

To mitigate CVE-2025-13120, organizations should promptly apply the official patch identified by commit eb398971bfb43c38db3e04528b68ac9a7ce509bc to all affected mruby versions up to 3.4.0. If immediate patching is not feasible, consider restricting local access to systems running mruby to trusted users only, minimizing the attack surface. Employ application whitelisting and monitoring to detect unusual behavior in processes using mruby. Conduct thorough code reviews and testing when embedding mruby in custom applications to identify potential misuse of the sort_cmp function or similar array operations. Additionally, implement least privilege principles for processes running mruby to limit the impact of potential exploitation. Regularly update and audit all dependencies, including mruby, to ensure timely application of security fixes. Finally, maintain robust logging and alerting mechanisms to detect exploitation attempts or crashes related to this vulnerability.

Description

A vulnerability has been found in mruby up to 3.4.0. This vulnerability affects the function sort_cmp of the file src/array.c. Such manipulation leads to use after free. An attack has to be approached locally. The exploit has been disclosed to the public and may be used. The name of the patch is eb398971bfb43c38db3e04528b68ac9a7ce509bc. It is advisable to implement a patch to correct this issue.

References

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