How severe is CVE-2026-9791?

CVE-2026-9791 has a CVSS score of 4.3/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2026-9791?

CVE-2026-9791 affects the following packages: org.keycloak:keycloak-server-spi-private (Maven), org.keycloak:keycloak-services (Maven), org.keycloak:keycloak-server-spi-private (Maven), org.keycloak:keycloak-services (Maven). Ecosystems affected: Maven.

How do I fix CVE-2026-9791?

Update org.keycloak:keycloak-server-spi-private to 26.6.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-9791 is resolved across your whole dependency graph.

How do I detect CVE-2026-9791 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.keycloak:keycloak-server-spi-private, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-9791 if there is no patch (or I can't update yet)?

Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Is CVE-2026-9791 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-9791 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-9791?

CVE-2026-9791 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 29th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-9791?

CVE-2026-9791 is classified as CWE-863 (CWE-863). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-9791 published, and has it been updated?

CVE-2026-9791 was published on May 28, 2026 and was last updated on July 1, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕

☕ Maven

Not in CISA KEV

MEDIUM severity

CVE-2026-9791 — keycloak-server-spi-priva…

MEDIUMFix: keycloak/keycloak#49541

CVE-2026-9791 is a medium-severity (CVSS 4.3) CWE-863 vulnerability in org.keycloak:keycloak-server-spi-private. A fix is available for org.keycloak:keycloak-server-spi-private — see the affected versions and patch details below.

Keycloak Vulnerable to Incorrect Authorization

Published

May 28, 2026

Updated

Jul 1, 2026

Affected

4 pkgs

Patched

2 / 4

Exploits

None indexed

Exploitation data as of Oct 8, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-9791.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs29th percentile — riskier than 29% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2026-9791 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 384,993 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

4 pkgs affected

☕org.keycloak:keycloak-server-spi-private☕org.keycloak:keycloak-services☕org.keycloak:keycloak-server-spi-private☕org.keycloak:keycloak-services

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

A flaw was found in Keycloak. An authenticated user with existing organization membership can exploit this flaw by accessing user-facing APIs, such as the account API or by requesting an OpenID Connect (OIDC) token with the 'organization' scope. This allows organization metadata to be disclosed in tokens, even after an administrator has explicitly disabled the Organizations feature, potentially leading to incorrect authorization decisions by resource servers.

Affected Packages

4 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.keycloak:keycloak-server-spi-private`	≥ 26.5.0&&< 26.6.3	26.6.3`org.keycloak:keycloak-server-spi-private:26.6.3`
☕Maven	`org.keycloak:keycloak-services`	≥ 26.5.0&&< 26.6.3	26.6.3`org.keycloak:keycloak-services:26.6.3`
☕Maven	`org.keycloak:keycloak-server-spi-private`	all versions	No fix
☕Maven	`org.keycloak:keycloak-services`	all versions	No fix

Affected Products

1 product · 1 configurations

Application

build of keycloakredhat

all

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.keycloak:keycloak-server-spi-private, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.keycloak:keycloak-server-spi-private to 26.6.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-9791 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate

Keycloak fails to enforce the disabled state of the Organizations feature on user-facing APIs, allowing authenticated users to retrieve organization membership data and obtain tokens with organization claims even after an administrator has disabled the feature at the realm level.

Workaround published by Red Hat

Administrators should verify that disabling the Organizations feature properly blocks all organization-related functionality. Consider implementing additional access controls or removing organization memberships before disabling the feature.

Source: Red Hat security advisory for CVE-2026-9791 (CC BY 4.0)

Product	Fixed in	Advisory
Red Hat build of Keycloak 26.4	`rhbk/keycloak-operator-bundle:26.4.13-1`	RHSA-2026:30050
Red Hat build of Keycloak 26.4.13	`rhbk/keycloak-rhel9`	RHSA-2026:30049
Red Hat build of Keycloak 26.6	`rhbk/keycloak-operator-bundle:26.6.3-3`	RHSA-2026:25097
Red Hat build of Keycloak 26.6.3	`rhbk/keycloak-rhel9`	RHSA-2026:25098

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2026-9791 in your dependencies?

Find it across Maven, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

4.3/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

None

Raw vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

CWE Classification

CWE-863CWE-863

Weaponization

No known public exploit tooling found.

OpenSSF Scorecard

Package health score

keycloak

9.3/10

Maintained10/10

Code-Review10/10

Branch-Protection8/10

Assessed Oct 5, 2026

Timeline

Disclosed

May 28, 2026

Last updated

Jul 1, 2026

Identifiers

CVE-2026-9791

References

Advisorynvd.nist.gov Webgithub.com Webgithub.com Webgithub.com Webgithub.com Webgithub.com Webgithub.com Webgithub.com Webaccess.redhat.com Webaccess.redhat.com Webaccess.redhat.com Webaccess.redhat.com Webaccess.redhat.com Webbugzilla.redhat.com Packagegithub.com

Related vulnerabilities

Also affects keycloak-server-spi-private

This CVE is medium severity; 5 of 6 other CVEs affecting keycloak-server-spi-private are rated as high or higher (top: high).

CVE-2026-9704CVE-2026-3190CVE-2026-2603CVE-2026-0871CVE-2023-2585CVE-2020-10776

Also affects keycloak-services

This CVE is medium severity; 2 of 2 other CVEs affecting keycloak-services are rated as high or higher (top: critical).

CVE-2026-18963CVE-2026-2092

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedJul 1, 2026

CVE-2026-9791 — keycloak-server-spi-priva…

Exploitation Status

No confirmed exploitation observed yet

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Fixing This On Your OS

Frequently Asked Questions

Is CVE-2026-9791 in your dependencies?