# CVE-2026-30040: Memory corruption in n/a

> Attackers can execute arbitrary code by tricking users into opening a crafted JPEG 2000 file in FastStone Image Viewer.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 26 Jun 2026
- **Updated:** 26 Jun 2026
- **Also known as:** GHSA-74rp-5fx4-84m7

## What is CVE-2026-30040?

CVE-2026-30040 is a medium-severity memory corruption vulnerability in n/a, published on 26 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A heap overflow in the FSViewer.exe process of FastStone Image Viewer v8.3 allows attackers to cause a execute arbitrary code in the context of the current process via supplying a crafted JPEG 2000 (JP2) file.

Weakness: CWE-122 (Heap-based Buffer Overflow)

## Which versions are affected by CVE-2026-30040?


## How do I fix CVE-2026-30040?

No fix has been published for CVE-2026-30040 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-30040 being exploited?

There is no known exploitation of CVE-2026-30040 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-30040 and fix it if it is affected.

What it is: CVE-2026-30040 is a medium-severity memory corruption vulnerability in n/a, published on 26 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-30040 in the wild and no public exploit code.

Affected product: n/a. 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-2026-30040/ (Markdown: https://insights.sbomify.com/CVE-2026-30040/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-30040
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-30040
- OSV: https://osv.dev/vulnerability/CVE-2026-30040

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-30040/
Summaries are generated and may contain mistakes; the official description above is the record.