# CVE-2026-3713: pnggroup libpng pnm2png pnm2png.c do_pnm2png heap-based overflow

> A heap-based buffer overflow in libpng's pnm2png utility allows local attackers to execute arbitrary code or cause denial of service.

- **Severity:** Medium 4.8 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 8 Mar 2026
- **Updated:** 11 Mar 2026
- **Also known as:** AZL-79506, AZL-79512, AZL-79515, AZL-79517, AZL-79520, AZL-79523, AZL-79631, AZL-79646, AZL-79652, DEBIAN-CVE-2026-3713, GHSA-fgc7-hpwc-cmc9, UBUNTU-CVE-2026-3713

## What is CVE-2026-3713?

CVE-2026-3713 is a medium-severity memory corruption vulnerability in pnggroup libpng, published on 8 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A flaw has been found in pnggroup libpng up to 1.6.55. Affected by this vulnerability is the function do_pnm2png of the file contrib/pngminus/pnm2png.c of the component pnm2png. This manipulation of the argument width/height causes heap-based buffer overflow. The attack is restricted to local execution. The exploit has been published and may be used. The project was informed of the problem early through an issue report but has not responded yet.

Weakness: CWE-122 (Heap-based Buffer Overflow), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2026-3713?


## How do I fix CVE-2026-3713?

No fix published yet.

## Is CVE-2026-3713 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-3713 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-3713 and fix it if it is affected.

What it is: CVE-2026-3713 is a medium-severity memory corruption vulnerability in pnggroup libpng, published on 8 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-3713 exists.

Affected product: pnggroup libpng. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-3713/ (Markdown: https://insights.sbomify.com/CVE-2026-3713/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-3713
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-3713
- OSV: https://osv.dev/vulnerability/CVE-2026-3713

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-3713/
Summaries are generated and may contain mistakes; the official description above is the record.