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

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.

Published: 2026-06-02 Last update: 2026-06-04 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-47201 is rated Moderate Risk (40.9/100): CVSS High severity, with low exploitation likelihood (EPSS 0.06%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-47201

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-03 — 0.06% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-47201

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.5 3.1 HIGH
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 6.0 [email protected]

Weakness enumeration for CVE-2026-47201

GitHub Security Advisory for CVE-2026-47201

GHSA-c3m2-jqmq-pvp3 · Severity: high · Ecosystem: go — authentik's XML Signature Wrapping in SAML Source ACS allows authentication as arbitrary federated user

Affected software / configurations for CVE-2026-47201

Vendor Product Version Raw CPE
goauthentik authentik < 2025.12.6 cpe:2.3:a:goauthentik:authentik:*:*:*:*:*:*:*:*
goauthentik authentik >= 2026.2.0, < 2026.2.4 cpe:2.3:a:goauthentik:authentik:*:*:*:*:*:*:*:*
goauthentik authentik >= 2026.5.0, < 2026.5.1 cpe:2.3:a:goauthentik:authentik:*:*:*:*:*:*:*:*

References for CVE-2026-47201

cvelogic Threat Intelligence