CVE-2023-6544 | Keycloak: authorization bypass

A flaw was found in the Keycloak package. This issue occurs due to a permissive regular expression hardcoded for filtering which allows hosts to register a dynamic client. A malicious user with enough information about the environment could jeopardize an environment with this specific Dynamic Client Registration and TrustedDomain configuration previously unauthorized.

Published: 2024-04-25 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Deferred，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-6544 is rated Moderate Risk (42.5/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.07%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-6544

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 1.31% 1.07% -0.23%
2 2026-04-09 1.00% 1.31% +0.30%
3 2026-03-15 — 1.00% —

Full EPSS history (13 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-6544

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.4 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 2.5 [email protected]

Weakness enumeration for CVE-2023-6544

GitHub Security Advisory for CVE-2023-6544

GHSA-46c8-635v-68r2 · Severity: medium · Ecosystem: maven — Keycloak Authorization Bypass vulnerability

OS Trackers for CVE-2023-6544

vendor priority summary link
redhat medium — https://access.redhat.com/security/cve/CVE-2023-6544

Affected software / configurations for CVE-2023-6544

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2023-6544

cvelogic Threat Intelligence