MrubyApplication

CVE-2025-13120

MEDIUM · 5.5 CVSS v3.1 Published 2025-11-13
Fix available
A fix is available. Upgrade to after 3.4.0 or later.
See remediation →
57/100
Remediation priority · Elevated
Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-119

The program reads or writes outside the bounds of an allocated buffer, corrupting adjacent memory. With crafted input an attacker can overwrite control data and, with effort, redirect execution to their own code. Remediation ranges from bounds checking and safe library functions to compiler mitigations, usually alongside a careful audit of the surrounding code.

General guidance for the memory buffer bounds error class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
MrubyApplication
Affected:<= 3.4.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 3.4.0
Vendor patch github.com →
Recommended fix Moderate confidence

mruby 3.5.0 or later (or the latest stable makesoftwaresafe mruby release containing commit eb398971bfb43c38db3e04528b68ac9a7ce509bc)

  1. 1. Identify the current mruby version in your deployment using `mruby --version` or checking your dependency files
  2. 2. If using a package manager or dependency management system, update mruby to the latest stable release that includes the security fix
  3. 3. Verify the fix is included by checking the changelog or release notes for the new version
  4. 4. Rebuild any applications or services that depend on mruby with the updated version
  5. 5. Run your test suite to ensure compatibility with the updated mruby version
  6. 6. Deploy the updated version to your production environment
Caveat Review release notes for any behavioral changes between 3.4.x and the target version, though no major breaking changes are typically expected for point releases

Generated from the published advisory — verify against the referenced sources before acting.

We can identify the exact fixed release, upgrade, and verify it in staging — typical engagement from $2,850. Get the upgrade done

Scan for this in your stack

Free · runs locally
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Check whether your project pulls in CVE-2025-13120 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-13120 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data