# CVE-2024-21637: XSS in Authentik via JavaScript-URI as Redirect URI and form_post Response Mode

> Attackers can execute arbitrary scripts via JavaScript URIs in OpenID Connect flows, potentially leading to privilege escalation in Authentik.

- **Severity:** High 7.7 (`CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 11 Jan 2024
- **Updated:** 17 Jun 2025
- **Also known as:** BIT-authentik-2024-21637, GHSA-rjpr-7w8c-gv3j

## What is CVE-2024-21637?

CVE-2024-21637 is a high-severity cross-site scripting vulnerability in goauthentik authentik, published on 11 Jan 2024. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

### Official description

Authentik is an open-source Identity Provider. Authentik is a vulnerable to a reflected Cross-Site Scripting vulnerability via JavaScript-URIs in OpenID Connect flows with `response_mode=form_post`. This relatively user could use the described attacks to perform a privilege escalation. This vulnerability has been patched in versions 2023.10.6 and 2023.8.6.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2024-21637?

1 open source package ship an affected version, including authentik. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `authentik` | Bitnami | From 2023.8.0 | 2023.8.6, 2023.10.6 |

Products: Goauthentik Authentik.

## How do I fix CVE-2024-21637?

Upgrade authentik to a fixed version for your release line: 2023.8.6 or 2023.10.6.

## Is CVE-2024-21637 being exploited?

There is no known exploitation of CVE-2024-21637 in the wild and no public exploit code.

## Other vulnerabilities in goauthentik authentik

- [CVE-2026-49448](https://insights.sbomify.com/CVE-2026-49448/): authentik: SourceStage bypass via empty POST (critical 9.8)
- [CVE-2023-46249](https://insights.sbomify.com/CVE-2023-46249/): authentik potential installation takeover when default admin user is deleted (critical 9.7)
- [CVE-2022-23555](https://insights.sbomify.com/CVE-2022-23555/): authentik vulnerable to Improper Authentication via invitation URL token reuse (critical 9.4)
- [CVE-2026-42849](https://insights.sbomify.com/CVE-2026-42849/): authentik: Reflected XSS in SFE AutosubmitStage allows IDP account takeover (critical 9.3)
- [CVE-2026-25227](https://insights.sbomify.com/CVE-2026-25227/): authentik affected by Remote Code Execution via Context Key Injection in PropertyMapping Test Endpoint (critical 9.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-21637 and fix it if it is affected.

What it is: CVE-2024-21637 is a high-severity cross-site scripting vulnerability in goauthentik authentik, published on 11 Jan 2024. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2024-21637 in the wild and no public exploit code.

Affected packages and fixed versions:
- authentik (Bitnami): affected from 2023.8.0; fixed in 2023.8.6, 2023.10.6

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-2024-21637/ (Markdown: https://insights.sbomify.com/CVE-2024-21637/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-21637
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-21637
- OSV: https://osv.dev/vulnerability/CVE-2024-21637

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-21637/
Summaries are generated and may contain mistakes; the official description above is the record.