# CVE-2020-26539: Use after free in n/a

> A use-after-free vulnerability in Foxit Reader allows remote attackers to execute arbitrary code or leak information via crafted PDF files.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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:** Not needed
- **Fix available:** No
- **Published:** 2 Oct 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-x9q9-5gcc-4mvx

## What is CVE-2020-26539?

CVE-2020-26539 is a critical use after free vulnerability in Foxitsoftware Foxit Reader, published on 2 Oct 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An issue was discovered in Foxit Reader and PhantomPDF before 10.1. When there is a multiple interpretation error for /V (in the Additional Action and Field dictionaries), a use-after-free can occur with resultant remote code execution (or an information leak).

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2020-26539?

It affects 2 products.


Products: Foxitsoftware Foxit Reader, Foxitsoftware Phantompdf.

## How do I fix CVE-2020-26539?

No fix has been published for CVE-2020-26539 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-26539 being exploited?

There is no known exploitation of CVE-2020-26539 in the wild and no public exploit code.

## Other vulnerabilities in Foxitsoftware Foxit Reader

- [CVE-2021-33793](https://insights.sbomify.com/CVE-2021-33793/): Memory corruption in n/a (critical 9.8)
- [CVE-2021-38568](https://insights.sbomify.com/CVE-2021-38568/): Memory corruption in n/a (critical 9.8)
- [CVE-2021-38572](https://insights.sbomify.com/CVE-2021-38572/): Path traversal in n/a (critical 9.8)
- [CVE-2021-38573](https://insights.sbomify.com/CVE-2021-38573/): Path traversal in n/a (critical 9.8)
- [CVE-2021-38574](https://insights.sbomify.com/CVE-2021-38574/): SQL injection in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-26539 and fix it if it is affected.

What it is: CVE-2020-26539 is a critical use after free vulnerability in Foxitsoftware Foxit Reader, published on 2 Oct 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-26539 in the wild and no public exploit code.

Affected product: Foxitsoftware Foxit 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-2020-26539/ (Markdown: https://insights.sbomify.com/CVE-2020-26539/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-26539
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-26539
- OSV: https://osv.dev/vulnerability/CVE-2020-26539

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-26539/
Summaries are generated and may contain mistakes; the official description above is the record.