CVE-2026-16442: Keycloak-services: keycloak-services: saml idp-initiated broker login bypasses link-only restriction
Noroxi assessment
Priority: Monitor (action score 39/100)
- 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: 0.31% (FIRST EPSS).
- 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 the record, no fixed version is available yet.
- Severity is disputed: the assigning authority (CNA) scores it 7.4, NVD 9.8.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
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 SAML broker component of Keycloak, which is used to manage identity federation and user authentication. The issue occurs because the IdP-initiated Single Sign-On endpoint fails to check if a provider is restricted to account linking only. This allows an attacker with control over a linked upstream identity to bypass login restrictions and gain full access to a local user account.
- Published
- Aug 5, 2026
- Updated
- Aug 31, 2026
- EPSS
- 0.3% · 24th percentile
- CWE
- CWE-346
Report tools
Action score
39
Monitor
Low priority for now.
- CVSS
- 39 / 40 · 9.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.3%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 9.8
- CNA · redhat
- 7.4
- 2.4 point gap
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
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.
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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.
| Vendor | Product | CPE |
|---|---|---|
| redhat | build of keycloak | cpe:2.3:a:redhat:build_of_keycloak |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- redhat build of keycloak26.4 and later · before 26.4.14
- redhat build of keycloak26.6 and later · before 26.6.5
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
- 26.4.14-1 and laternot affected · rpm
- 26.4-22 and laternot affected · rpm
- 26.4-22 and laternot affected · rpm
Red Hat Red Hat build of Keycloak 26.4.14
- all versionsunknown
- all versionsunknown
Red Hat Red Hat build of Keycloak 26.6
- 26.6.5-1 and laternot affected · rpm
- 26.6-11 and laternot affected · rpm
- 26.6-11 and laternot affected · rpm
Red Hat Red Hat build of Keycloak 26.6.5
- all versionsunknown
- all versionsunknown
- all versionsunknown
Red Hat Red Hat Data Grid 8
- all versionsunknown
Red Hat Red Hat JBoss Enterprise Application Platform Expansion Pack
- all versionsunknown
Red Hat Red Hat Single Sign-On 7
- all versionsunknown
Same product
redhat: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-16443Keycloak-services: keycloak-services: saml broker metadata import disables response signature validation36Monitor
- CVE-2026-15572Keycloak-services: keycloak-services: dcr protocol mapper type-swap policy bypass allows privilege escalation35Monitor
- CVE-2026-9704Keycloak: keycloak: privilege escalation due to oversized subject_token jwt35Monitor
Published before and after this one in the same product
- ← EarlierCVE-2026-16100Aug 5, 2026 · Keycloak-services: keycloak-services: unbounded metric cardinality in user event metrics via request-controlled error text26Monitor
- ← EarlierCVE-2026-16102Aug 5, 2026 · Keycloak-services: keycloak-services: default dcr policy allows role forgery via user property mappers32Monitor
- Later →CVE-2026-18967Aug 6, 2026 · Keycloak-services: keycloak-services: saml onetimeuse assertion replay in idp-initiated broker flow32Monitor
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.
- Paul Bottinelli (TrailBits in collaboration with OpenAI) for reporting this issue.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2026-37977121 days apartKeycloak: org.keycloak.protocol.oidc.grants.ciba: keycloak: information disclosure via cors header injection due to unvalidated jwt azp claim21Monitor
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).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-26-0761 · Aug 6, 2026(Red Hat Keycloak Güvenlik Bildirimi)
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
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-346 · Origin Validation ErrorCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
nvd-primary
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)
- JSON Hijacking (aka JavaScript Hijacking)CAPEC-111likelihood: High · High
- Cache PoisoningCAPEC-141likelihood: High · High
- DNS Cache PoisoningCAPEC-142likelihood: High · High
- Exploit Script-Based APIsCAPEC-160Medium
- Exploitation of Trusted IdentifiersCAPEC-21likelihood: High · High
- Application API Message Manipulation via Man-in-the-MiddleCAPEC-384Low
- Transaction or Event Tampering via Application API ManipulationCAPEC-385Medium
- Application API Navigation RemappingCAPEC-386Medium
ATT&CK techniques
- Access Token ManipulationT1134
- Access Token Manipulation:Token Impersonation/TheftT1134.001
- Steal Application Access TokenT1528
- Steal Web Session CookieT1539
- Use Alternate Authentication Material:Web Session CookieT1550.004
- Adversary-in-the-Middle: ARP Cache PoisoningT1557.002
- Compromise Infrastructure: DNS ServerT1584.002
Change log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
Show all references (5 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.