# CVE-2026-91807: Foxit PDF Reader heap-based out-of-bounds read in image soft-mask parsing

Source: https://junglewise.ai/threats/cve-2026-91807-a-heap-based-out-of-bounds-read-vulnerability-exists-in-foxit-pdf  
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-2026-91807 · Severity: medium · CVSS 6.1 · Published 2026-09-23

Foxit PDF Reader and Editor are widely-used applications for viewing and editing PDF documents in business environments. A flaw in how they process malformed image data can cause the application to crash by reading memory beyond allocated boundaries, disrupting user work but not leading to data theft or system compromise.

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-2026-91807 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-91807 being exploited in the wild.

**How severe is CVE-2026-91807?** Medium severity, with a CVSS score of 6.1, published 23 September 2026.

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

**Is there a fix for CVE-2026-91807?** A patch was published on 2026-09-23: Foxit PDF Reader 2026.2.1 and Foxit PDF Editor 2026.2.1/14.0.8 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-91807 attacked?** It is attacked with local access.

**Am I affected by CVE-2026-91807?** 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

A heap-based out-of-bounds read exists in the image soft-mask parsing logic due to insufficient validation of soft-mask data attributes. Arithmetic underflow during image parsing causes the application to read beyond heap boundaries, resulting in a denial of service via application crash. The vulnerability requires user interaction (opening a malicious PDF) and is triggered at parse time with no authentication needed.

## Affected products

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

## Timeline

- 2026-09-23: disclosed
- 2026-09-23: patched: Foxit PDF Reader 2026.2.1 and Foxit PDF Editor 2026.2.1/14.0.8 released

## References

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

## Related threats

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