# CVE-2008-3964: Integer overflow in n/a

> Off-by-one errors in libpng allow attackers to cause a denial of service via crafted PNG images with malicious zTXt chunks.

- **Severity:** Medium 4.3 (`AV:N/AC:M/Au:N/C:N/I:N/A:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 10 Sep 2008
- **Updated:** 7 Aug 2024
- **Also known as:** GHSA-fj2p-r342-gx3m

## What is CVE-2008-3964?

CVE-2008-3964 is a medium-severity vulnerability in Libpng Libpng, published on 10 Sep 2008. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Multiple off-by-one errors in libpng before 1.2.32beta01, and 1.4 before 1.4.0beta34, allow context-dependent attackers to cause a denial of service (crash) or have unspecified other impact via a PNG image with crafted zTXt chunks, related to (1) the png_push_read_zTXt function in pngread.c, and possibly related to (2) pngtest.c.

Weakness: CWE-193 (Off-by-one Error)

## Which versions are affected by CVE-2008-3964?

It affects 1 product.


Products: Libpng Libpng.

## How do I fix CVE-2008-3964?

Upgrade to a fixed version.

## Is CVE-2008-3964 being exploited?

There is no known exploitation of CVE-2008-3964 in the wild and no public exploit code.

## Other vulnerabilities in Libpng Libpng

- [CVE-2017-12652](https://insights.sbomify.com/CVE-2017-12652/): Denial of service in n/a (critical 9.8)
- [CVE-2018-14550](https://insights.sbomify.com/CVE-2018-14550/): Out-of-bounds write in libpng (high 8.8)
- [CVE-2026-25646](https://insights.sbomify.com/CVE-2026-25646/): LIBPNG has a heap buffer overflow in png_set_quantize (high 8.3)
- [CVE-2026-33636](https://insights.sbomify.com/CVE-2026-33636/): LIBPNG has ARM NEON Palette Expansion Out-of-Bounds Read on AArch64 (high 7.6)
- [CVE-2026-33416](https://insights.sbomify.com/CVE-2026-33416/): LIBPNG has use-after-free via pointer aliasing in `png_set_tRNS` and `png_set_PLTE` (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2008-3964 and fix it if it is affected.

What it is: CVE-2008-3964 is a medium-severity vulnerability in Libpng Libpng, published on 10 Sep 2008. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2008-3964 in the wild and no public exploit code.

Affected product: Libpng 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-2008-3964/ (Markdown: https://insights.sbomify.com/CVE-2008-3964/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2008-3964
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2008-3964
- OSV: https://osv.dev/vulnerability/CVE-2008-3964

---
From sbomify Insights: https://insights.sbomify.com/CVE-2008-3964/
Summaries are generated and may contain mistakes; the official description above is the record.