# CVE-2018-3850: Use after free in Foxit

> A use-after-free vulnerability in Foxit PDF Reader allows arbitrary code execution via a malicious PDF or website.

- **Severity:** High 8.8 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **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 Apr 2018
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-q248-6jpv-6wjh

## What is CVE-2018-3850?

CVE-2018-3850 is a high-severity use after free vulnerability in Foxit Pdf Reader, published on 23 Apr 2018. 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

An exploitable use-after-free vulnerability exists in the JavaScript engine Foxit Software Foxit PDF Reader version 9.0.1.1049. A specially crafted PDF document can trigger a previously freed object in memory to be reused, resulting in arbitrary code execution. An attacker needs to trick the user to open the malicious file to trigger this vulnerability. If a browser plugin extension is enabled, visiting a malicious site can also trigger the vulnerability.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2018-3850?

It affects 1 product.


Products: Foxit Pdf Reader.

## How do I fix CVE-2018-3850?

No fix has been published for CVE-2018-3850 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-3850 being exploited?

There is no known exploitation of CVE-2018-3850 in the wild and no public exploit code.

## Other vulnerabilities in Foxit Pdf Reader

- [CVE-2021-38563](https://insights.sbomify.com/CVE-2021-38563/): Null dereference in n/a (critical 9.8)
- [CVE-2025-32451](https://insights.sbomify.com/CVE-2025-32451/): Memory corruption in Foxit Reader (high 8.8)
- [CVE-2024-28888](https://insights.sbomify.com/CVE-2024-28888/): Use after free in Foxit Reader (high 8.8)
- [CVE-2023-27379](https://insights.sbomify.com/CVE-2023-27379/): Use after free in Foxit Reader (high 8.8)
- [CVE-2023-28744](https://insights.sbomify.com/CVE-2023-28744/): Use after free in Foxit Reader (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-3850 and fix it if it is affected.

What it is: CVE-2018-3850 is a high-severity use after free vulnerability in Foxit Pdf Reader, published on 23 Apr 2018. 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-2018-3850 in the wild and no public exploit code.

Affected product: Foxit Pdf Reader. 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-2018-3850/ (Markdown: https://insights.sbomify.com/CVE-2018-3850/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-3850
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-3850
- OSV: https://osv.dev/vulnerability/CVE-2018-3850

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-3850/
Summaries are generated and may contain mistakes; the official description above is the record.