SEPTEMBER 21, 2026
Live Feed
Back to database
Case File

CVE-2026-9803

MEDIUM · CVSS 5.3 EPSS 0.42% Public Exploit

Source: NVD + CISA KEV + EPSS (historical backfill) · Published 2026-05-28 · Last synced 2026-08-04

CyberRota Analysis

This is a medium severity vulnerability with a CVSS score of 5.3. Public exploit code or proof-of-concept references have been detected in its references. It may be remotely exploitable. Exploitation may require the attacker to be authenticated. It may lead to a denial-of-service condition.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Detected Signals
exploit

Note: these links are listed for security research and verification purposes only.

CVE
CVE-2026-9803
Severity
MEDIUM
CVSS
5.3
EPSS
0.42%

Original NVD Description

A flaw was found in Keycloak's ClientRegistrationAuth component. A remote unauthenticated attacker can exploit this vulnerability by sending a specially crafted POST request with a malformed 'Authorization: Bearer' header to any client registration endpoint. This can lead to an ArrayIndexOutOfBoundsException, causing the server to return an HTTP 500 error and resulting in a Denial of Service (DoS) for the affected service.

Related CVEs

Other vulnerabilities affecting the same vendor(s)