Keycloak has Incorrect Behavior Order: Authorization Before Parsing and CanonicalizationGHSA-gv94-wp4h-vv8p
MEDIUMGHSA-gv94-wp4h-vv8p is a medium-severity (CVSS 5.3) CWE-551 vulnerability in org.keycloak:keycloak-parent. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-gv94-wp4h-vv8p.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
org.keycloak:keycloak-parentReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
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 Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.keycloak:keycloak-parent | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.keycloak:keycloak-parent, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
The records we use list no patched version of org.keycloak:keycloak-parent for GHSA-gv94-wp4h-vv8p. Check the maintainer's advisory, and where your build allows, override or pin the dependency away from the vulnerable range.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
This vulnerability is rated Moderate for Red Hat because Keycloak's excessive tolerance for non-standard Bearer token formats in the Authorization header can lead to inconsistencies with front-end security controls such as WAFs and proxies. This may enable potential bypass risks, allowing malformed tokens to…
To mitigate this issue, configure any front-end security controls, such as Web Application Firewalls (WAFs) or reverse proxies, to strictly validate and normalize the `Authorization` header before forwarding requests to Keycloak. This ensures that only standard Bearer token formats are processed, preventing potential bypasses.Source: Red Hat security advisory for GHSA-gv94-wp4h-vv8p (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat build of Keycloak 26.4 | rhbk/keycloak-operator-bundle:26.4.10-1 | RHSA-2026:3948 |
| Red Hat build of Keycloak 26.4.10 | rhbk/keycloak-rhel9 | RHSA-2026:3947 |
Frequently Asked Questions
Is GHSA-gv94-wp4h-vv8p in your dependencies?
Find it across Maven, including transitive dependencies.