# CVE-2026-25748: authentik has a forward authentication bypass with broken cookie

> Attackers can bypass authentication in authentik Proxy Provider using a malformed cookie when integrated with Traefik or Caddy.

- **Severity:** High 8.6 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 12 Feb 2026
- **Updated:** 17 Feb 2026
- **Also known as:** BIT-authentik-2026-25748, GHSA-fj56-5763-j8pp

## What is CVE-2026-25748?

CVE-2026-25748 is a high-severity authentication bypass vulnerability in goauthentik authentik, published on 12 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

authentik is an open-source identity provider. Prior to 2025.10.4 and 2025.12.4, with a malformed cookie it was possible to bypass authentication when using forward authentication in the authentik Proxy Provider when used in conjunction with Traefik or Caddy as reverse proxy. When a malicious cookie was used, none of the authentik-specific X-Authentik-* headers were set which depending on application can grant access to an attacker. authentik 2025.10.4 and 2025.12.4 fix this issue.

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2026-25748?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `authentik` | Bitnami | From 2025.10.0 | 2025.12.4 |

Products: Goauthentik Authentik.

## How do I fix CVE-2026-25748?

Upgrade authentik to 2025.12.4 or later.

## Is CVE-2026-25748 being exploited?

There is no known exploitation of CVE-2026-25748 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-2026-25748 and fix it if it is affected.

What it is: CVE-2026-25748 is a high-severity authentication bypass vulnerability in goauthentik authentik, published on 12 Feb 2026. 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-2026-25748 in the wild and no public exploit code.

Affected packages and fixed versions:
- authentik (Bitnami): affected from 2025.10.0; fixed in 2025.12.4

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-2026-25748/ (Markdown: https://insights.sbomify.com/CVE-2026-25748/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-25748
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-25748
- OSV: https://osv.dev/vulnerability/CVE-2026-25748

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-25748/
Summaries are generated and may contain mistakes; the official description above is the record.