# CVE-2026-101204: FastStone Image Viewer TGA Image FSViewer.exe out-of-bounds

> An out-of-bounds read in FastStone Image Viewer's TGA handler allows remote attackers to cause denial of service or disclose information.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E: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:** No
- **Published:** 28 Sep 2026
- **Updated:** 1 Oct 2026
- **Also known as:** GHSA-39cx-9v2h-jx3h

## What is CVE-2026-101204?

CVE-2026-101204 is a medium-severity memory corruption vulnerability in FastStone Image Viewer, published on 28 Sep 2026. 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

A vulnerability was found in FastStone Image Viewer up to 8.3. This affects an unknown function of the file FSViewer.exe of the component TGA Image Handler. The manipulation results in out-of-bounds read. The attack can be launched remotely. The vendor was contacted early about this disclosure but did not respond in any way.

Weakness: CWE-125 (Out-of-bounds Read), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2026-101204?


## How do I fix CVE-2026-101204?

No fix has been published for CVE-2026-101204 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-101204 being exploited?

There is no known exploitation of CVE-2026-101204 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-101204 and fix it if it is affected.

What it is: CVE-2026-101204 is a medium-severity memory corruption vulnerability in FastStone Image Viewer, published on 28 Sep 2026. 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-2026-101204 in the wild and no public exploit code.

Affected product: FastStone Image Viewer. 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-2026-101204/ (Markdown: https://insights.sbomify.com/CVE-2026-101204/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-101204
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-101204
- OSV: https://osv.dev/vulnerability/CVE-2026-101204

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-101204/
Summaries are generated and may contain mistakes; the official description above is the record.