# CVE-2026-91802: Foxit PDF Editor heap-based buffer overflow in WebP decoding

Source: https://junglewise.ai/threats/cve-2026-91802-a-heap-based-out-of-bounds-write-vulnerability-exists-in-foxit  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-23. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-91802 · Severity: high · CVSS 7.8 · Published 2026-09-23

Foxit PDF Editor and Reader contain a heap-based out-of-bounds write vulnerability in WebP image decoding that occurs when processing malformed WebP images. An attacker can exploit this by crafting a malicious PDF containing a specially crafted WebP image, leading to application crash, information disclosure, or potentially remote code execution when a user opens the PDF.

Technologies: [Foxit PDF Editor](https://junglewise.ai/threats/technologies/pdf-editor), [Foxit PDF Reader](https://junglewise.ai/threats/technologies/pdf-reader). Vendors: [Foxit](https://junglewise.ai/threats/vendors/foxit).

## Quick answers

**Is CVE-2026-91802 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-91802 being exploited in the wild.

**How severe is CVE-2026-91802?** High severity, with a CVSS score of 7.8, published 23 September 2026.

**Which products and versions are affected?** Foxit PDF Editor 2026.2.0.39747 and earlier (2026.x versions), 2025.3.0.35737 and earlier (2025.x versions), 2024.4.1.27687 and earlier (2024.x versions), 2023.3.0.23028 and earlier (2023.x versions), 14.0.7.33751 and earlier (14.x versions), 13.2.6.24111 and earlier; Foxit PDF Reader 2026.2.0.39747 and earlier.

**Is there a fix for CVE-2026-91802?** A patch was published on 2026-09-23: Fixed in Foxit PDF Reader 2026.2.1 and Foxit PDF Editor 2026.2.1/14.0.8 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-91802 attacked?** It is attacked with local access, in a software library.

**Am I affected by CVE-2026-91802?** Check whether you run Foxit PDF Editor or Foxit PDF Reader at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability stems from improper handling of bitmap stride and target buffer formats during WebP image decoding in Foxit's PDF processing engine. An unauthenticated attacker can trigger an out-of-bounds write by supplying a malformed WebP image embedded in a PDF file, requiring only user interaction to open the document. Successful exploitation could result in application crash, information disclosure, or arbitrary code execution depending on memory layout and attacker precision.

## Affected products

- Foxit PDF Reader 2026.2.0.39747 and earlier
- Foxit PDF Editor 2026.2.0.39747 and earlier (2026.x versions), 2025.3.0.35737 and earlier (2025.x versions), 2024.4.1.27687 and earlier (2024.x versions), 2023.3.0.23028 and earlier (2023.x versions), 14.0.7.33751 and earlier (14.x versions), 13.2.6.24111 and earlier

## Timeline

- 2026-09-23: disclosed: Security bulletin published
- 2026-09-23: patched: Fixed in Foxit PDF Reader 2026.2.1 and Foxit PDF Editor 2026.2.1/14.0.8

## References

- [https://www.foxit.com/support/security-bulletins.html](https://www.foxit.com/support/security-bulletins.html)

## Related threats

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- [Foxit PDF Editor heap-based out-of-bounds read in JavaScript string handling](https://junglewise.ai/threats/cve-2026-91817-a-heap-based-out-of-bounds-read-vulnerability-exists-in-foxit-pdf)
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