# CVE-2026-91797: Foxit PDF Editor/Reader directory traversal in attachment file name

Source: https://junglewise.ai/threats/cve-2026-91797-foxit-pdf-editor-reader-failed-to-validate-the-directory  
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-2026-91797 · Severity: high · CVSS 7.8 · Published 2026-09-23

Foxit PDF Editor and Reader are widely used desktop applications for creating, editing, and viewing PDF documents. A vulnerability in how these applications handle attachment file names allows malicious PDF files to extract attachments outside the intended secure directory when opened, potentially overwriting system files or placing malware on the user's computer. No active exploitation in the wild has been reported.

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-2026-91797 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-91797 being exploited in the wild.

**How severe is CVE-2026-91797?** 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 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-2026-91797?** 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-2026-91797 attacked?** It is attacked with local access, in a software library.

**Am I affected by CVE-2026-91797?** 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 is a directory traversal flaw in attachment file name validation that allows path traversal sequences (e.g., "../") in embedded file names to escape the secure attachment directory. An attacker can craft a malicious PDF with specially crafted attachment file names that, when the PDF is opened and the attachment is extracted, write files to arbitrary locations on the file system. The flaw affects multiple versions across both products; patches are available in Foxit PDF Reader 2026.2.1 and Foxit PDF Editor 2026.2.1/14.0.8 and later.

## 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

- [Foxit PDF Editor use-after-free in JavaScript annotation handling](https://junglewise.ai/threats/cve-2026-91818-a-use-after-free-vulnerability-exists-in-foxit-pdf-editor-reader)
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- [Foxit PDF Editor use-after-free in annotation handling](https://junglewise.ai/threats/cve-2026-91816-a-use-after-free-vulnerability-exists-in-foxit-pdf-editor-reader)
- [Foxit PDF Editor/Reader out-of-bounds write in JPEG2000 decoding](https://junglewise.ai/threats/cve-2026-91815-foxit-pdf-editor-reader-does-not-perform-sufficient-verification)
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