Vulnerability · Published Jun 2, 2026 · Assigned by GitHub_M

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

High 8.5

In plain English

A high-severity improper input validation in authentik from goauthentik. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 8% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.5High

Exploit odds (30 days)0.2%top 92.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Go	goauthentik.io	0.0.0-20260528144335-a370d76d23c7	GHSA-c3m2-jqmq-pvp3

Affected products (as reported)

Vendor	Product	Versions
goauthentik	authentik	< 2025.12.5< 2026.2.3< 2026.5.1

Weakness: CWE-20 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

References

https://github.com/goauthentik/authentik/security/advisories/GHSA-c3m2-jqmq-pvp3 x_refsource_CONFIRM