CVE-2026-47203
📛 CVE Title
(no title)
Description
Authelia Missing Username Canonicalization in Basic Auth (LDAP)
Description (MITRE) cveawg.mitre.org
Pulled from cveawg.mitre.org/api/cve/CVE-2026-47203 on 2026-07-27. Shown when MITRE's text differs from the cvelistV5 mirror.
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.
Overview
- State
- —
- Assigner (CNA)
- —
- CVSS severity
- high
- CVSS score
- 7.5 / 10
- CVSS vector
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N- Effective score
- 7.5 / 10 HIGH source: CNA overview
- CWE(s)
- —
- Reserved
- —
- Published
- —
- Last updated
- —
- Source
- https://www.tenable.com/cve/CVE-2026-47203
- Linked Threat
- CVE-2026-47203 — CVE-2026-47203
NVD triage scoring NVD CVE 2.0
Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.
- NVD published
- 2026-06-19 21:16:57 UTC
- NVD last modified
- 2026-06-23 16:06:25 UTC
- EPSS score
- 0.0045 (probability of exploitation in next 30 days)
- EPSS percentile
- 36.95% vs all CVEs — higher = more likely to be exploited, as of 2026-07-26
NVD-assigned CWE(s):
CWE-178,
CWE-307
(differs from the CNA list above)
NVD / KEV / EPSS data refreshed 2026-07-27 14:00 UTC. Re-run the 🛰 Backfill from NVD button above to refresh.
European Union Vulnerability Database ENISA EUVD
ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.
- EUVD ID
-
EUVD-2026-38082 - Assigner
- GitHub_M
- Published
- Jun 19, 2026, 8:19:47 PM
- Updated
- Jun 22, 2026, 6:13:48 PM
- EUVD base score (CVSS 4.0)
-
2.9 / 10
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 - EUVD-reported EPSS
- 0.4500
- Vendors
- authelia
- Products
-
authelia (4.38.0, < 4.39.20)
- Aliases
-
GHSA-hjj4-hfjm-fmrj
ENISA 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.
Vendor references (0)
References embedded in the original CVE record by the assigning CNA.
None in the CVE record.
MITRE references (2) cveawg.mitre.org
Pulled from MITRE's CVE Services API by the 🛰 Backfill from MITRE button.
Web references (2)
DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.
- https://nvd.nist.gov/vuln/detail/CVE-2026-47203 tenable:nvd.nist.gov
- https://www.cve.org/CVERecord?id=CVE-2026-47203 tenable:www.cve.org
NVD-tagged references (2)
Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.
- https://github.com/authelia/authelia/commit/b8985b57b70acdff8f204ed426ff619e763461ad security-advisories@github.com
- https://github.com/authelia/authelia/security/advisories/GHSA-hjj4-hfjm-fmrj security-advisories@github.com
Remediations (10)
Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.
-
web:blog.qualys.com
May 2026's Patch Tuesday arrives with Microsoft addressing a fresh set of vulnerabilities across its ecosystem, reinforcing the ongoing need for timely patching in an increasingly threat-heavy…
2026-06-19 02:30 UTC -
web:cybersecuritynews.com
Microsoft has officially acknowledged a critical zero-day vulnerability in Microsoft Defender, publicly dubbed "RoguePlanet," and confirmed it is actively developing a security patch to address the flaw.
2026-06-19 02:30 UTC -
web:cybersecuritynews.com
Microsoft's May 2026 Patch Tuesday lands with a heavy enterprise focus, fixing 120 vulnerabilities across Windows, Office, Azure, developer tools, and Microsoft 365 apps, including 29 remote code execution (RCE) flaws rated Critical.
2026-06-19 02:30 UTC -
web:portal.msrc.microsoft.com
The Security Update Guide provides information on the latest Microsoft security updates, helping users understand and address potential vulnerabilities effectively.
2026-06-19 02:30 UTC -
web:www.cisecurity.org
<p>Multiple vulnerabilities have been discovered in Microsoft products, the most severe of which could allow for remote code execution. Successful exploitation of the most severe of these vulnerabilities could result in an attacker gaining the same privileges as the logged-on user. Depending on the privileges associated with the user, an attacker could then install programs; view, change, or ...
2026-06-19 02:30 UTC -
web:www.computerworld.com
Microsoft says it is considering a patch for a zero-day vulnerability, dubbed YellowKey, that allows attackers with access to a Windows device to bypass Bitlocker encryption protection and read ...
2026-06-19 02:30 UTC -
web:www.csoonline.com
Microsoft released emergency fixes for two zero-day vulnerabilities in the malware protection components of Microsoft Defender. The flaws allow local attackers to gain system-level privileges or ...
2026-06-19 02:30 UTC -
web:www.malwarebytes.com
Microsoft says it's working on a fix for an unpatched Defender vulnerability that can give attackers the highest level of access on Windows.
2026-06-19 02:30 UTC -
web:www.microsoft.com
Security Update Guide Notifications Microsoft's free Security Update Guide Notifications provide links to security-related software updates and notification of re-released security updates. These notifications are sent via email throughout the month as needed.
2026-06-19 02:30 UTC -
web:zecurit.com
Get the complete breakdown of Microsoft's June 2026 Patch Tuesday. We analyze the latest security updates and all critical CVEs .
2026-06-19 02:30 UTC
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