# CVE-2026-5939: UAF in Foxit PDF Editor/Reader via XFA calculate event

> A crafted XFA PDF triggers a use-after-free in Foxit PDF Editor/Reader, allowing attackers to execute arbitrary code or cause a crash.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 27 Apr 2026
- **Updated:** 28 Apr 2026
- **Also known as:** GHSA-242w-wcg6-2fc6

## What is CVE-2026-5939?

CVE-2026-5939 is a medium-severity use after free vulnerability in Foxit Pdf Editor, published on 27 Apr 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

A crafted XFA PDF can trigger a use-after-free condition during calculate event processing, causing the application to crash and resulting in an arbitrary code execution.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2026-5939?

It affects 2 products.


Products: Foxit Pdf Editor, Foxit Pdf Reader.

## How do I fix CVE-2026-5939?

No fix has been published for CVE-2026-5939 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-5939 being exploited?

There is no known exploitation of CVE-2026-5939 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-2026-5939 and fix it if it is affected.

What it is: CVE-2026-5939 is a medium-severity use after free vulnerability in Foxit Pdf Editor, published on 27 Apr 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-5939 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-2026-5939/ (Markdown: https://insights.sbomify.com/CVE-2026-5939/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-5939
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-5939
- OSV: https://osv.dev/vulnerability/CVE-2026-5939

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-5939/
Summaries are generated and may contain mistakes; the official description above is the record.