CVE-2026-47203

June 19, 2026, 9:16 p.m.

2.9
Low

Description

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.

Product(s) Impacted

Vendor Product Versions
Authelia
  • Authelia
  • 4.38.0-4.39.19, 4.39.20

Weaknesses

Common security weaknesses mapped to this vulnerability.

CWE-178
Improper Handling of Case Sensitivity
The product does not properly account for differences in case sensitivity when accessing or determining the properties of a resource, leading to inconsistent results.

*CPE(s)

Affected systems and software identified for this CVE.

Type Vendor Product Version Update Edition Language Software Edition Target Software Target Hardware Other Information
a authelia authelia 4.38.0-4.39.19 / / / / / / /
a authelia authelia 4.39.20 / / / / / / /

References

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

Tags

[email protected]
CWE-178
2026-06-19
CVE-2026-47203

CVSS Score

2.9 / 10

CVSS Data - 4.0

  • Attack Vector: NETWORK
  • Attack Complexity: HIGH
  • Attack Requirements: PRESENT
  • Privileges Required: NONE
  • User Interaction: NONE
  • Scope:
  • Confidentiality Impact: LOW
  • Integrity Impact: NONE
  • Availability Impact: NONE
  • Exploit Maturity: PROOF_OF_CONCEPT

    • CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

    View Vector String

Timeline

Published: June 19, 2026, 9:16 p.m.
Last Modified: June 19, 2026, 9:16 p.m.

Status : Received

CVE has been recently published to the CVE List and has been received by the NVD.

More info

Source

[email protected]

*Disclaimer: Some vulnerabilities do not have an associated CPE. To enhance the data, we use AI to infer CPEs based on CVE details. This is an automated process and might not always be accurate.