# CVE-2026-58489: HedgeDoc: CSRF in GitHub Gist export callback

> Attackers can trick logged-in users into exporting private notes to attacker-controlled GitHub Gists via a CSRF vulnerability in the OAuth callback.

- **Severity:** Medium 6.8 (`CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:A/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 13 Jul 2026
- **Updated:** 14 Jul 2026
- **Also known as:** GHSA-8v9p-5j95-826j

## What is CVE-2026-58489?

CVE-2026-58489 is a medium-severity vulnerability in hedgedoc, published on 13 Jul 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

HedgeDoc is an open source, real-time collaborative markdown notes application. Prior to 1.11.0, the GitHub Gist export flow created an OAuth2  state  value but only checked that it was present rather than validating it against the value expected for the user's session. Because the state was not properly validated, an attacker could forge a callback URL containing their own valid GitHub OAuth code. When processing the callback, HedgeDoc used the victim's logged-in session to select which note to export, but the attacker's authorization code to determine which GitHub account received it. As a result, a logged-in victim who clicked a crafted link could export their own private, protected, or limited note directly into a Gist controlled by the attacker. This issue has been fixed in version 1.11.0.

Weakness: CWE-352 (Cross-Site Request Forgery)

## Which versions are affected by CVE-2026-58489?


## How do I fix CVE-2026-58489?

No fix has been published for CVE-2026-58489 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-58489 being exploited?

There is no known exploitation of CVE-2026-58489 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-58489 and fix it if it is affected.

What it is: CVE-2026-58489 is a medium-severity vulnerability in hedgedoc, published on 13 Jul 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-58489 in the wild and no public exploit code.

Affected product: hedgedoc. 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-2026-58489/ (Markdown: https://insights.sbomify.com/CVE-2026-58489/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-58489
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-58489
- OSV: https://osv.dev/vulnerability/CVE-2026-58489

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-58489/
Summaries are generated and may contain mistakes; the official description above is the record.