# CVE-2026-3778: Stack exhaustion caused by cyclic references in Foxit PDF Editor/Reader

> Attackers can crash Foxit PDF Editor or Reader by crafting PDFs with cyclic references that trigger stack exhaustion during deep traversal.

- **Severity:** Medium 6.2 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/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:** Not needed
- **Fix available:** No
- **Published:** 1 Apr 2026
- **Updated:** 2 Apr 2026
- **Also known as:** GHSA-hfjq-v5wc-856q

## What is CVE-2026-3778?

CVE-2026-3778 is a medium-severity denial of service vulnerability in Foxit Pdf Editor, published on 1 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The application does not detect or guard against cyclic PDF object references while handling JavaScript in PDF. When pages and annotations are crafted that reference each other in a loop, passing the document to APIs (e.g., SOAP) that perform deep traversal can cause uncontrolled recursion, stack exhaustion, and application crashes.

Weakness: CWE-674 (Uncontrolled Recursion)

## Which versions are affected by CVE-2026-3778?

It affects 2 products.


Products: Foxit Pdf Editor, Foxit Pdf Reader.

## How do I fix CVE-2026-3778?

No fix has been published for CVE-2026-3778 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-3778 being exploited?

There is no known exploitation of CVE-2026-3778 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-2026-3778 and fix it if it is affected.

What it is: CVE-2026-3778 is a medium-severity denial of service vulnerability in Foxit Pdf Editor, published on 1 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-3778 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-2026-3778/ (Markdown: https://insights.sbomify.com/CVE-2026-3778/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-3778
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-3778
- OSV: https://osv.dev/vulnerability/CVE-2026-3778

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-3778/
Summaries are generated and may contain mistakes; the official description above is the record.