# CVE-2026-47201: authentik: XML Signature Wrapping in SAML Source ACS allows authentication as arbitrary federated user

> Attackers can authenticate as arbitrary federated users via XML Signature Wrapping in SAML responses, requiring an upgrade to patched versions.

- **Severity:** High 8.5 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/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:** Yes
- **Published:** 2 Jun 2026
- **Updated:** 3 Jun 2026
- **Also known as:** BIT-authentik-2026-47201, GHSA-c3m2-jqmq-pvp3

## What is CVE-2026-47201?

CVE-2026-47201 is a high-severity authentication bypass vulnerability in goauthentik authentik, published on 2 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

authentik is an open-source identity provider. Prior to versions 2025.12.5, 2026.2.3, and 2026.5.1, authentik's SAML Source ACS endpoint is vulnerable to XML Signature Wrapping when validating upstream SAML responses. An attacker with any account at the upstream IdP can reuse a valid signed assertion to authenticate as another federated user. This issue has been patched in versions 2025.12.5, 2026.2.3, and 2026.5.1.

Weakness: CWE-347 (Improper Verification of Cryptographic Signature), CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2026-47201?

3 open source packages ship an affected version, including goauthentik.io and authentik. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `goauthentik.io` | Go | All versions | 0.0.0-20260528144335-a370d76d23c7 |
| `goauthentik.io` | Go | All versions | 0.0.0-20260528144335-a370d76d23c7 |
| `authentik` | Bitnami | All versions | 2026.5.1 |

Products: Goauthentik Authentik.

## How do I fix CVE-2026-47201?

Upgrade goauthentik.io to 0.0.0-20260528144335-a370d76d23c7 or later.

## Is CVE-2026-47201 being exploited?

There is no known exploitation of CVE-2026-47201 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-2026-47201 and fix it if it is affected.

What it is: CVE-2026-47201 is a high-severity authentication bypass vulnerability in goauthentik authentik, published on 2 Jun 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-2026-47201 in the wild and no public exploit code.

Affected packages and fixed versions:
- goauthentik.io (Go): affected all versions; fixed in 0.0.0-20260528144335-a370d76d23c7
- goauthentik.io (Go): affected all versions; fixed in 0.0.0-20260528144335-a370d76d23c7
- authentik (Bitnami): affected all versions; fixed in 2026.5.1

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-2026-47201/ (Markdown: https://insights.sbomify.com/CVE-2026-47201/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-47201
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-47201
- OSV: https://osv.dev/vulnerability/CVE-2026-47201

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-47201/
Summaries are generated and may contain mistakes; the official description above is the record.