CVE-2026-47203

Authelia is an open-source authentication and authorization server providing two-factor authentication and single sign-on (SSO) for applications via a web portal. In versions 4.38.0 through 4.39.19, when a user authenticates via Basic Auth (i.e via the `Authorization` header with the `Basic` scheme) on the authz verification endpoint, Authelia takes the username directly from the `Authorization` header and passes it as is to the regulation system for ban checking and attempt recording. LDAP treats usernames case insensitively : `john`, `John`, and `JOHN` all bind as the same user. But the regulation SQL queries treat the lookup of these values in certain scenarios as case sensitive. This allows each variation of a usernames case to have its own ban bucket. Upgrade to 4.39.20 to receive a patch. As a workaround, explicitly disable the basic auth mechanism.

CVSS

No CVSS.

References

Link	Resource
https://github.com/authelia/authelia/commit/b8985b57b70acdff8f204ed426ff619e763461ad
https://github.com/authelia/authelia/security/advisories/GHSA-hjj4-hfjm-fmrj

Configurations

No configuration.

History

19 Jun 2026, 21:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-06-19 21:16

Updated : 2026-06-22 19:16

NVD link : CVE-2026-47203

Mitre link : CVE-2026-47203

CVE.ORG link : CVE-2026-47203

JSON object : View

Products Affected

No product.

CWE

CWE-178

Improper Handling of Case Sensitivity

CWE-307

Improper Restriction of Excessive Authentication Attempts

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