CVE-2026-19607
CVE-2026-19607
A flaw was found in the first-broker-login flow of the keycloak-services component. This component handles the initial authentication and account linking when a user logs in via an external identity provider. The issue allows an attacker to register a matching username on an external provider to trigger a collision in Keycloak, which results in the legitimate user being locked out of their account.
Vulnerability class: Broken Authentication
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
EPSS exploit prediction
EPSS: 0.007 (52.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 53rd percentile — 52.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.007 · change: +0.002
Weakness classification (CWE)
Public proof-of-concept exploits
References
- access.redhat.com/errata/RHSA-2026:68276 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:68277 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:68278 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:68280 (vendor-advisory)
- access.redhat.com/security/cve/CVE-2026-19607 (vdb-entry)
- bugzilla.redhat.com/show_bug.cgi (issue-tracking)
Frequently asked questions
- What is CVE-2026-19607?
- CVE-2026-19607 is a medium-severity vulnerability, classified under Improper Authentication. CVSS score: 5.3/10. Published 2026-09-16.
- How severe is CVE-2026-19607?
- Medium severity. CVSS v3 base score is 5.3 out of 10.
- Is CVE-2026-19607 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.