authentik: XML Signature Wrapping in SAML Source ACS allows authentication as arbitrary federated user
Priority LOW 38CWE-20Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- High
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-347.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00182 7th percentileScored 2026-11-07
Fix Fixed authentik (goauthentik): 2025.12.5, 2026.2.3, 2026.5.1goauthentik.io (Go): 0.0.0-20260528144335-a370d76d23c7
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| goauthentik | authentik | before 2025.12.5; before 2026.2.3; before 2026.5.1 | 2025.12.5, 2026.2.3, 2026.5.1 | Patch available | CNA |
| — | goauthentik.io (Go) | before 0.0.0-20260528144335-a370d76d23c7 | 0.0.0-20260528144335-a370d76d23c7 | Patch available | GHSA-c3m2-jqmq-pvp3 |
- authentik Vendorgoauthentik Affected before 2025.12.5; before 2026.2.3; before 2026.5.1 Fixed in 2025.12.5, 2026.2.3, 2026.5.1 Patch available CNA
- goauthentik.io (Go) Vendor— Affected before 0.0.0-20260528144335-a370d76d23c7 Fixed in 0.0.0-20260528144335-a370d76d23c7 Patch available GHSA-c3m2-jqmq-pvp3
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:goauthentik:authentik:*:*:*:*:*:*:*:* | before 2025.12.6; 2026.2.0 to before 2026.2.4; 2026.5.0 to before 2026.5.1 | Vulnerable | goauthentik |
- cpe:2.3:a:goauthentik:authentik:*:*:*:*:*:*:*:* Versions before 2025.12.6; 2026.2.0 to before 2026.2.4; 2026.5.0 to before 2026.5.1 Vulnerable ·goauthentik
Remediation
- Fix · CNA authentik (goauthentik) Fixed in 2025.12.5, 2026.2.3, 2026.5.1
- Fix · GHSA-c3m2-jqmq-pvp3 goauthentik.io (Go) Fixed in 0.0.0-20260528144335-a370d76d23c7 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-47201
- 2026-10-03 Alias added: GHSA-c3m2-jqmq-pvp3
References
More goauthentik Authentik vulnerabilities
- TI-2026-36603 authentik: SourceStage bypass via empty POST CVSS 3.1CRITICAL 9.8
- TI-2022-07608 authentik vulnerable to Improper Authentication via invitation URL token reuse CVSS 3.1CRITICAL 9.4
- TI-2026-36598 authentik: `UserSourceConnection.user` and `GroupSourceConnection.group` are changeable through the API CVSS 3.1HIGH 8.8
- TI-2022-22816 authentik allows existing authenticated users to create arbitrary accounts CVSS 3.1MEDIUM 6.4
- TI-2024-25628 Insufficient access control for OAuth2 Device Code flow in authentik CVSS 3.1CRITICAL 9.8
- TI-2023-24876 authentik potential installation takeover when default admin user is deleted CVSS 3.1CRITICAL 9.8
Sources
- CVE-2026-47201 · CVE Program
- CVE-2026-47201 · NVD
- FIRST EPSS
- GHSA-c3m2-jqmq-pvp3 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences