CVE-2026-47201CWE-20

authentik: XML Signature Wrapping in SAML Source ACS allows authentication as arbitrary federated user

High · published June 2, 2026

CVSS v3.1
8.5
EPSS
0%
Percentile
19.7
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
8.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00283 · 19.7th percentile
Weakness
CWE-20 · Improper Input Validation
Published
2026-06-02T20:30Z
EPSS history
Timeline
  • 02 JUN 20:30Z
    authentik: XML Signature Wrapping in SAML Source ACS allows authentication as arbitrary federated user
    cvelistv5