CVE-2025-13120: A vulnerability has been found in mruby up to 3.4.0

Q: How do I fix CVE-2025-13120?

mruby: upgrade to newer than 3.4.0. Exact commands for each OS are on this page.

Q: Is CVE-2025-13120 being exploited?

CVE-2025-13120 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2025-13120 affect?

CVE-2025-13120 affects mruby. Severity is medium (CVSS 5.3). 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

Q: How urgent is CVE-2025-13120?

Priority 20/100. No elevated risk signals yet.

Routine

MEDIUM 5.3UPGRADE

CVE-2025-13120 is a medium-severity flaw (CVSS 5.3) affecting mruby. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	5.3 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.2% (top 95%)
CISA exploited list	No
Weakness	CWE-119, CWE-416
Published	2025-11-13
Last modified	2026-10-19

Publisher (CNA): VulDB · Vendor: mruby

Last updated 2026-10-19 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2025-11-13 16:15 UTCPublished CVE record published
2026-10-19 13:10 UTCUpdated Record last modified

mruby mruby UPGRADE

Affected: <= 3.4.0

Fixed in: newer than 3.4.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy mruby || rpm -q mruby || mruby --version

2. UPGRADE to newer than 3.4.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade mruby

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade mruby

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2025-13120?

mruby: upgrade to newer than 3.4.0. Exact commands for each OS are on this page.

Is CVE-2025-13120 being exploited?

CVE-2025-13120 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2025-13120 affect?

CVE-2025-13120 affects mruby. Severity is medium (CVSS 5.3). 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

How urgent is CVE-2025-13120?

Priority 20/100. No elevated risk signals yet.

Related CVEs

CVE-2025-12875 MEDIUM 5.3 DOWNGRADE A weakness has been identified in mruby 3.4.0
CVE-2026-1979 MEDIUM 5.3 UPGRADE A flaw has been found in mruby up to 3.4.0
CVE-2025-7207 LOW 3.3 UPGRADE A vulnerability, which was classified as problematic, was found in mruby up to 3.4.0-rc2

References

← Back to latest CVEs