# CVE-2026-91814: Security feature bypass in Foxit PDF Editor

> Attackers can modify signed PDF content without invalidating the signature, enabling content spoofing in Foxit PDF Editor and Reader.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 23 Sep 2026
- **Updated:** 23 Sep 2026
- **Also known as:** GHSA-c9r7-69j9-jq5j

## What is CVE-2026-91814?

CVE-2026-91814 is a medium-severity vulnerability in Foxit Pdf Editor, published on 23 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

A signature validation vulnerability exists in Foxit PDF Editor/Reader’s handling of incrementally updated PDF documents. Changes to visible document content may not invalidate the existing signature, allowing attackers to alter signed content and potentially carry out content spoofing while the document continues to appear validly signed.

Weakness: CWE-347 (Improper Verification of Cryptographic Signature)

## Which versions are affected by CVE-2026-91814?

It affects 2 products.


Products: Foxit Pdf Editor, Foxit Pdf Reader.

## How do I fix CVE-2026-91814?

No fix has been published for CVE-2026-91814 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-91814 being exploited?

There is no known exploitation of CVE-2026-91814 in the wild and no public exploit code.

## Other vulnerabilities in Foxit Pdf Editor

- [CVE-2022-28104](https://insights.sbomify.com/CVE-2022-28104/): File upload in n/a (critical 9.8)
- [CVE-2022-24954](https://insights.sbomify.com/CVE-2022-24954/): Memory corruption in n/a (critical 9.8)
- [CVE-2022-24955](https://insights.sbomify.com/CVE-2022-24955/): Other in n/a (critical 9.8)
- [CVE-2026-91798](https://insights.sbomify.com/CVE-2026-91798/): Foxit PDF Editor/Reader Updater Privilege Escalation (high 8.8)
- [CVE-2026-91800](https://insights.sbomify.com/CVE-2026-91800/): Foxit PDF Editor installer local privilege escalation (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-91814 and fix it if it is affected.

What it is: CVE-2026-91814 is a medium-severity vulnerability in Foxit Pdf Editor, published on 23 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-91814 in the wild and no public exploit code.

Affected product: Foxit Pdf Editor. 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-2026-91814/ (Markdown: https://insights.sbomify.com/CVE-2026-91814/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-91814
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-91814
- OSV: https://osv.dev/vulnerability/CVE-2026-91814

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-91814/
Summaries are generated and may contain mistakes; the official description above is the record.