GHSA-gv94-wp4h-vv8p CVE-2026-0707
Keycloak has Incorrect Behavior Order: Authorization Before Parsing and Canonicalization
- Severity
- 5.3 / 10
- Medium · CVSS 3.1
- Exploit chance (EPSS)
- 0.40%
- Chance of exploitation in the next 30 days. Higher than 34.61% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-551 Incorrect Behavior Order: Authorization Before Parsing and Canonicalization
- Fix
- None yet
- No fixed version published
Description
A flaw was found in Keycloak. The Keycloak Authorization header parser is overly permissive regarding the formatting of the "Bearer" authentication scheme. It accepts non-standard characters (such as tabs) as separators and tolerates case variations that deviate from RFC 6750 specifications.
Affected versions
Maven
| Package | Vulnerable | Fixed in |
|---|---|---|
| org.keycloak:keycloak-parent | <= 26.5.0 |
No fix yet |
How to fix
No fixed version has been published yet. Until one is, remove or replace the package, or turn off or isolate the affected feature. This page updates when a fix ships.
Severity breakdown
CVSS 3.1 5.3
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
Weakness
CWE-551: Incorrect Behavior Order: Authorization Before Parsing and Canonicalization
If a web server does not fully parse requested URLs before it examines them for authorization, it may be possible for an attacker to bypass authorization protection.
How to prevent it
- Architecture and Design: URL Inputs should be decoded and canonicalized to the application's current internal representation before being validated and processed for authorization. Make sure that your application does not decode the same input twice. Such errors could be used to bypass allowlist schemes by introducing dangerous inputs after they have been checked.
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-fwhw-chw4-gh37 Keycloak Server-Side Request Forgery (SSRF) vulnerability | Low | Also affects org.keycloak:keycloak-parent |
| GHSA-9hhc-pj4w-w5rv Keycloak Cross-site Scripting on OpenID connect login service | Medium | Also affects org.keycloak:keycloak-parent |
| GHSA-g8q8-fggx-9r3q Keycloak vulnerable to path traversal via double URL encoding | Critical | Also affects org.keycloak:keycloak-parent |
| GHSA-97g8-xfvw-q4hg Keycloak vulnerable to session takeover with OIDC offline refreshtokens | Medium | Also affects org.keycloak:keycloak-parent |
| GHSA-w9mf-83w3-fv49 Keycloak vulnerable to Stored Cross site Scripting (XSS) when loading default roles | Medium | Also affects org.keycloak:keycloak-parent |
| GHSA-wf7g-7h6h-678v Keycloak SAML javascript protocol mapper: Uploading of scripts through admin console | High | Also affects org.keycloak:keycloak-parent |
| GHSA-xv7h-95r7-595j Incorrect implementation of lockout feature in Keycloak | High | Also affects org.keycloak:keycloak-parent |
| GHSA-jf86-9434-f8c2 Keycloak Authentication Error | Critical | Also affects org.keycloak:keycloak-parent |
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