CVE-2026-19607: Keycloak-services: keycloak-services: broker-originated username collision causes account lockout
Noroxi assessment
Priority: Monitor (action score 21/100)
- Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.68% (FIRST EPSS); higher than 52.7% of all records.
- Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
- According to CISA the attack is automatable: targets can be found by mass scanning.
- According to the record, no fixed version is available yet.
Low priority for now. Update when a fix is released; follow the vendor's advisory.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
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.
- Published
- Sep 16, 2026
- Updated
- Sep 16, 2026
- EPSS
- 0.6% · 52th percentile
- CWE
- CWE-287
Report tools
Action score
21
Monitor
Low priority for now.
- CVSS
- 21 / 40 · 5.3 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.6%
CISA SSVC decision
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · redhat
- 5.3
- NVD has not scored this yet; the score shown is the CNA’s.
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- Proof of concept exists, no weaponized module
- No fixed version yet
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (redhat). Independent of NVD's CPE analysis and usually ahead of it.
Red Hat Red Hat build of Keycloak 26.4
- 26.4.16-2 and laternot affected · rpm
- 26.4-26 and laternot affected · rpm
- 26.4-26 and laternot affected · rpm
Red Hat Red Hat build of Keycloak 26.4.16
- all versionsunknown
- all versionsunknown
Red Hat Red Hat build of Keycloak 26.6
- 26.6.7-3 and laternot affected · rpm
- 26.6-20 and laternot affected · rpm
- 26.6-20 and laternot affected · rpm
Red Hat Red Hat build of Keycloak 26.6.7
- all versionsunknown
- all versionsunknown
Red Hat Red Hat Single Sign-On 7
- all versionsunknown
Same product
red hat: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-18963Keycloak-services: keycloak-services: unauthenticated account takeover via reset-credentials flow bypass37Monitor
- CVE-2026-1486Org.keycloak.protocol.oidc.grants: disabled identity providers are still accepted for jwt authorization grant35Monitor
- CVE-2026-74909Keycloak-services: keycloak-services: incomplete fix for cve-2026-15573 allows policy enforcer bypass via percent-encoded uri segments32Monitor
Published before and after this one in the same product
- ← EarlierCVE-2026-18212Sep 16, 2026 · Keycloak-services: keycloak-services: saml redirect deflate helpers leak native zlib state30Monitor
- ← EarlierCVE-2026-79651Sep 16, 2026 · Keycloak-services: keycloak-services: unauthenticated dos via unbounded locale caching30Monitor
- ← EarlierCVE-2026-17526Sep 16, 2026 · Keycloak-services: keycloak-services: privilege escalation via impersonation role allows takeover of realm administrator accounts28Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
No fix version is recorded for this entry. Check the references for vendor advisories.
Exploit status
Proof of concept available
A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.
Evidence
- Proof-of-concept repository on GitHub ×1
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Proof-of-concept repository on GitHub | stars:3 | 2026-08-08 |
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
- First PoC-40 d
- Published
- TodayNov 6, 2026+51 d
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
—
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
- CVE-2026-749090 days apartKeycloak-services: keycloak-services: incomplete fix for cve-2026-15573 allows policy enforcer bypass via percent-encoded uri segments32Monitor
- CVE-2026-197297 days apartKeycloak-services: keycloak-services: incomplete fix for arbitrary filesystem path probing via keystore parameters19Monitor
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- low · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- Low
Weakness class (CWE)
CWE-287 · Improper AuthenticationCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
nvd-secondary
Root cause
Authentication is added route by route instead of being enforced in one place. When a route added later bypasses the shared middleware, the session check never runs for it.
The bug in code
The whole CWE-287 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
app.use("/admin", requireSession, adminRouter);
// Route added later skips the middleware
app.post("/admin-api/config", updateConfig);Fixed
const admin = express.Router();
admin.use(requireSession, requireRole("admin"));
admin.post("/config", updateConfig);
app.use("/admin", admin);Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Authentication AbuseCAPEC-114Medium
- Authentication BypassCAPEC-115Medium
- Identity SpoofingCAPEC-151likelihood: Medium · Medium
- Fake the Source of DataCAPEC-194Medium
- Exploiting Trust in ClientCAPEC-22likelihood: High · High
- Utilizing REST's Trust in the System Resource to Obtain Sensitive DataCAPEC-57likelihood: Medium · Very High
- Session HijackingCAPEC-593likelihood: High · Very High
- Token ImpersonationCAPEC-633Medium
ATT&CK techniques
Change log
- Exploit maturitynone → poc
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References
Show all references (5 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.