# CVE-2026-73539: Gitea external renderer argument injection and code execution

> Attackers can inject arguments into external renderer commands to execute arbitrary code as the service account if a susceptible renderer is configured.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 14 Oct 2026
- **Updated:** 18 Oct 2026
- **Also known as:** GHSA-579w-82gf-89m2

## What is CVE-2026-73539?

CVE-2026-73539 is a high-severity command injection vulnerability in Gitea, published on 14 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Gitea substitutes a URL derived from the markup Context field into external renderer command templates without escaping the reference path before shell-style argument splitting. A crafted Context can inject additional renderer arguments, including options that load executable filter files. On deployments using a susceptible external renderer such as pandoc, a user who can place a filter file at an accessible path can cause it to execute as the Gitea service account; the public repository markup endpoint itself can be reachable without authentication.

Weakness: CWE-88 (Improper Neutralization of Argument Delimiters in a Command)

## Which versions are affected by CVE-2026-73539?


## How do I fix CVE-2026-73539?

No fix has been published for CVE-2026-73539 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-73539 being exploited?

There is no known exploitation of CVE-2026-73539 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-73539 and fix it if it is affected.

What it is: CVE-2026-73539 is a high-severity command injection vulnerability in Gitea, published on 14 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-73539 in the wild and no public exploit code.

Affected product: Gitea. 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-2026-73539/ (Markdown: https://insights.sbomify.com/CVE-2026-73539/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-73539
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-73539
- OSV: https://osv.dev/vulnerability/CVE-2026-73539

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-73539/
Summaries are generated and may contain mistakes; the official description above is the record.