CVE-2017-12158
CWE-444Published: October 26, 2017· Updated: Jun 17, 2026
Official Description
It was found that Keycloak would accept a HOST header URL in the admin console and use it to determine web resource locations. An attacker could use this flaw against an authenticated user to attain reflected XSS via a malicious server.
Technical Analysis
CVE-2017-12158 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (10)
Quick Facts
Related CVEs (CWE-444)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2017-12158 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts