VulnerabilityPublished 19 May 2026Updated 20 May 2026

CVE-2026-37978: Red Hat build of Keycloak 26.4 · Insecure Direct Object Reference

Affects Red Hat build of Keycloak 26.4Source CVE Database V5

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Not known to be exploited · CVSS 4.9 Medium : upgrade Red Hat build of Keycloak 26.4 to 26.4.12 when convenient.

Data as of 29 Oct 2026, 19:04 UTC

CVSS 3.1 base score

4.9Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.4% chance of exploitation in 30 days – higher than 37% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 26.4.12

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: High
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: High: The attacker is authorized with (i.e., requires) privileges that provide significant (e.g., administrative) control over the vulnerable component that could affect component-wide settings and files.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 19 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade org.keycloak/keycloak to 26.4.12.

Affected software

Product	Affected	Fixed in
Mavenorg.keycloak/keycloak`pkg:maven/org.keycloak/keycloak`Other threats	Affected <26.4.12	Fixed in 26.4.12

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Red Hat has released an official security update in Red Hat build of Keycloak version 26.4.12 that addresses this vulnerability along with other security issues. Users should back up their existing installations, including configurations and databases, before applying the update. Applying this update is the recommended remediation. No alternative mitigations or temporary fixes are indicated in the vendor advisory.

Description

CVE-2026-37978 is a medium severity vulnerability in Red Hat build of Keycloak 26.4 where a low-privilege administrator with the 'view-clients' role can exploit the 'evaluate-scopes' Admin API endpoint by supplying an arbitrary user ID. This flaw allows unauthorized disclosure of personally identifiable information (PII) across user roles within the realm. The vulnerability can be exploited remotely via network access to the Admin API. Red Hat has released security updates in version 26.4.12 addressing this and other vulnerabilities. Users are advised to apply the update after backing up their installations.

Impact

The vulnerability allows unauthorized users with limited administrative privileges to access sensitive personally identifiable information (PII) of users across the realm, violating confidentiality. There is no impact on integrity or availability reported. Exploitation requires network access to the Admin API and a low-privilege administrator role. No known exploits in the wild have been reported at this time.

Summary

A vulnerability exists in Red Hat build of Keycloak 26.4 where a low-privilege administrator possessing the 'view-clients' role can invoke the 'evaluate-scopes' Admin API endpoint with an arbitrary userId parameter. This results in authorization bypass leading to cross-role leakage of personally identifiable information (PII), exposing user identities and authorizations beyond intended access controls. The vulnerability is remotely exploitable via network access to the Admin API. Red Hat has issued security advisories and released version 26.4.12 containing fixes for this issue along with several others.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 May 2026, 20:38 UTC

Technical details

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