# CVE-2022-39209: Uncontrolled Resource Consumption in cmark-gfm

> Attackers can cause denial of service in cmark-gfm via resource exhaustion when the autolink extension is enabled.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/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:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Sep 2022
- **Updated:** 23 Apr 2025
- **Also known as:** DEBIAN-CVE-2022-39209, GHSA-cgh3-p57x-9q7q, UBUNTU-CVE-2022-39209

## What is CVE-2022-39209?

CVE-2022-39209 is a high-severity denial of service vulnerability in Fedoraproject Fedora, published on 15 Sep 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

cmark-gfm is GitHub's fork of cmark, a CommonMark parsing and rendering library and program in C. In versions prior to 0.29.0.gfm.6 a polynomial time complexity issue in cmark-gfm's autolink extension may lead to unbounded resource exhaustion and subsequent denial of service. Users may verify the patch by running `python3 -c 'print("![l"* 100000 + "\n")' | ./cmark-gfm -e autolink`, which will resource exhaust on unpatched cmark-gfm but render correctly on patched cmark-gfm. This vulnerability has been patched in 0.29.0.gfm.6. Users are advised to upgrade. Users unable to upgrade should disable the use of the autolink extension.

Weakness: CWE-407 (Inefficient Algorithmic Complexity), CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2022-39209?

It affects 2 products.


Products: Fedoraproject Fedora, Github Cmark-Gfm.

## How do I fix CVE-2022-39209?

Upgrade to a fixed version.

## Is CVE-2022-39209 being exploited?

There is no known exploitation of CVE-2022-39209 in the wild and no public exploit code.

## Other vulnerabilities in Fedoraproject Fedora

- [CVE-2024-4577](https://insights.sbomify.com/CVE-2024-4577/): PHP-CGI OS Command Injection (critical 9.8, exploited in the wild)
- [CVE-2021-39226](https://insights.sbomify.com/CVE-2021-39226/): Grafana Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2019-5544](https://insights.sbomify.com/CVE-2019-5544/): VMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2024-4947](https://insights.sbomify.com/CVE-2024-4947/): Google Chromium V8 Type Confusion (critical 9.6, exploited in the wild)
- [CVE-2024-4671](https://insights.sbomify.com/CVE-2024-4671/): Google Chromium Visuals Use-After-Free (critical 9.6, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-39209 and fix it if it is affected.

What it is: CVE-2022-39209 is a high-severity denial of service vulnerability in Fedoraproject Fedora, published on 15 Sep 2022. 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-2022-39209 in the wild and no public exploit code.

Affected product: Fedoraproject Fedora. 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-2022-39209/ (Markdown: https://insights.sbomify.com/CVE-2022-39209/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-39209
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-39209
- OSV: https://osv.dev/vulnerability/CVE-2022-39209

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-39209/
Summaries are generated and may contain mistakes; the official description above is the record.