CVE-2026-41569

authentik: WS-Federation wreply origin bypass can exfiltrate signed login responses to attacker-controlled endpoints

State: Published
Severity: 6.9 Medium
Published: Jun 2, 2026
Updated: Jun 3, 2026
Reserved: Apr 21, 2026

Description

authentik is an open-source identity provider. Prior to version 2026.2.3, the WS-Federation provider validates the user-supplied wreply parameter using a raw string prefix check rather than proper URL parsing. An attacker who can craft a login link can supply a wreply value on a different origin that passes the check (e.g. https://portal.example.com.evil.tld/), causing the victim's browser to POST the signed WS-Federation login response to attacker-controlled infrastructure. This issue has been patched in version 2026.2.3.

Scores

CVSS	Score	Vector	Source
4.0	6.9 Medium	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N	GitHub_M

Weaknesses

CWE-601 URL Redirection to Untrusted Site ('Open Redirect')

Affected Products

Product	Versions
authentikgoauthentik	< 2026.2.3Affected

References

https://github.com/goauthentik/authentik/security/advisories/GHSA-995q-72cw-cfw3

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