How severe is CVE-2026-37979?

No CVSS score has been assigned to CVE-2026-37979 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-37979?

CVE-2026-37979 affects the following packages: keycloak (Bitnami). Ecosystems affected: Bitnami.

How do I fix CVE-2026-37979?

Update keycloak to 26.4.12 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-37979 is resolved across your whole dependency graph.

How do I detect CVE-2026-37979 in my Bitnami dependencies?

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

How do I mitigate CVE-2026-37979 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-2026-37979 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-37979 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-2026-37979?

CVE-2026-37979 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 33th 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-2026-37979?

CVE-2026-37979 is classified as CWE-284 (CWE-284). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-37979 published, and has it been updated?

CVE-2026-37979 was published on August 25, 2026 and was last updated on September 8, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2026-37979: keycloak — Fixed in 26.4.12

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-2026-37979.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk+0.05%

Lower risk than most CVEs33th percentile — riskier than 33% of all scored CVEsHighest risk

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

Real-World Exposure

1 pkg affected

📦keycloak

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

Description

A flaw was found in Keycloak. This access control vulnerability in Keycloak's OpenID Connect (OIDC) token introspection endpoint allows a confidential client to bypass audience restrictions. An attacker-controlled client with valid credentials can retrieve sensitive token claims intended for other resource servers, compromising the confidentiality of lightweight access tokens. This issue can be exploited remotely by any confidential client in the realm with valid credentials.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦Bitnami	`keycloak`	≥ 26.4.0&&< 26.4.12	26.4.12

Affected Products

1 product · 1 configurations

Application

build of keycloakredhat

≥ 26.4 && < 26.4.12

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for keycloak, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update keycloak to 26.4.12 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-37979 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

Moderate impact: Keycloak's OIDC token introspection endpoint fails to enforce audience validation, allowing a confidential client to retrieve sensitive token claims intended for a different audience. This compromises the confidentiality of lightweight tokens within Red Hat Build of Keycloak.

Workaround published by Red Hat

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

Source: Red Hat security advisory for CVE-2026-37979 (CC BY 4.0)

Product	Fixed in	Advisory
Red Hat build of Keycloak 26.4	`rhbk/keycloak-operator-bundle:26.4.12-1`	RHSA-2026:19597
Red Hat build of Keycloak 26.4.12	`rhbk/keycloak-rhel9`	RHSA-2026:19596

Frequently Asked Questions

A flaw was found in Keycloak. This access control vulnerability in Keycloak's OpenID Connect (OIDC) token introspection endpoint allows a confidential client to bypass audience restrictions. An attacker-controlled client with valid credentials can retrieve sensitive token claims intended for other resource servers, compromising the confidentiality of lightweight access tokens. This issue can be exploited remotely by any confidential client in the realm with valid credentials.

O3 Security · Impact-Aware SCA

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CVE-2026-37979 — keycloak