Keycloak-services: keycloak-services: potential kdc spoofing bypass when kerberos password authentication is enabled
Noroxi assessment
Priority: Monitor (action score 27/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.19% (FIRST EPSS).
- Someone on the same network segment can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
- 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 Kerberos federation provider of Keycloak, an open-source identity and access management solution. When Kerberos password authentication is used without SPNEGO, the system fails to verify the identity of the Key Distribution Center (KDC) by requesting a server ticket. This allows an attacker on the same network to spoof the KDC and bypass the authentication process, potentially gaining unauthorized access to user accounts.
- Published
- Sep 22, 2026
- Updated
- Sep 22, 2026
- EPSS
- 0.1% · 8th percentile
- CWE
- CWE-347
Report tools
Action score
27
Monitor
Low priority for now.
- CVSS
- 27 / 40 · 6.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.1%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · redhat
- 6.8
- 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
- No public exploit code on record
- No fixed version yet
If any of these changes, we'll tell you in the daily email digest.
Running WordPress? Scan your site free with WP Lens
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
- all versionsaffected
- all versionsaffected
- all versionsaffected
Red Hat Red Hat Single Sign-On 7
- all versionsaffected
Same product
red hat: all recordsOther highest-scoring records for the same primary product.
- CVE-2024-3656Keycloak: unguarded admin rest api endpoints allows low privilege users to use administrative functionalities33Monitor
- CVE-2025-3501Org.keycloak.protocol.services: keycloak hostname verification32Monitor
- CVE-2024-8698Keycloak-saml-core: improper verification of saml responses leading to privilege escalation in keycloak31Monitor
Published before and after this one in the same product
- ← EarlierCVE-2026-94217Sep 21, 2026 · Keycloak-services: keycloak-services: uma scope merge across resource owners via resource name collision14Monitor
- ← EarlierCVE-2026-94218Sep 21, 2026 · Keycloak-services: keycloak-services: 2fa setup enforcement bypass via authentication session restart endpoint12Monitor
- Later →CVE-2026-96445Sep 23, 2026 · Keycloak-services: keycloak-services: conditional otp skip-header policy evaluated against untrusted proxy headers27Monitor
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
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
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.
No dated events beyond publication.
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.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Someone on the same network segment can trigger it.
- No account or password is required.
- No user action is required.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- none
- Attack vector
- Adjacent
- Attack complexity
- High
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- None
Weakness class (CWE)
CWE-347 · Improper Verification of Cryptographic SignatureCVSS vector
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
nvd-secondary
Root cause
The verifier takes the algorithm to verify with from the token’s own header. Untrusted data ends up deciding its own verification rule.
The bug in code
The whole CWE-347 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
const claims = jwt.verify(token, publicKey);Fixed
const claims = jwt.verify(token, publicKey, {
algorithms: ["RS256"],
issuer: "https://id.example.com",
audience: "portal",
});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)
ATT&CK techniques
—
Change log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
Show all references (1 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.