VulnerabilityPublished 12 Mar 2026Updated 2 Apr 2026

CVE-2026-2366: 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 3.1 Low.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score

3.1Low

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 20% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: High
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: Low
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: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
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: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
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 12 Mar 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 30 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

Affected software

Product	Affected	Fixed in
Red HatRed Hat build of Keycloak 26.4	Affected–	Fixed in–
Red HatRed Hat build of Keycloak 26.4	Affected–	Fixed in–
Red HatRed Hat build of Keycloak 26.4.11	Affected–	Fixed in–

AI-suggested

To mitigate CVE-2026-2366, organizations should first verify whether the Organizations feature in Keycloak is enabled and assess the necessity of this feature. If not required, disabling the Organizations feature can eliminate the attack surface. For environments where the feature is essential, strict access controls should be enforced to limit authenticated user permissions and prevent unnecessary access to the Admin API endpoints. Monitoring and logging of Admin API access should be enhanced to detect unusual enumeration patterns or access attempts involving user UUIDs. Organizations should implement strong authentication mechanisms to reduce the risk of compromised accounts being used to exploit this vulnerability. Until an official patch or update is released by Red Hat, consider applying custom API gateway rules or filters to restrict access to organization membership enumeration endpoints. Regularly review Keycloak release notes and security advisories for patches addressing this issue and apply updates promptly. Additionally, educate users and administrators about the risk of sharing UUIDs or other identifiers that could facilitate exploitation.

Description

A flaw was found in Keycloak. An authorization bypass vulnerability in the Keycloak Admin API allows any authenticated user, even those without administrative privileges, to enumerate the organization memberships of other users. This information disclosure occurs if the attacker knows the victim's unique identifier (UUID) and the Organizations feature is enabled.

Impact

The primary impact of CVE-2026-2366 is limited information disclosure regarding user organization memberships within Keycloak deployments. For organizations, this could lead to exposure of internal organizational structures or membership details, which might aid attackers in reconnaissance or social engineering attacks. While the vulnerability does not allow privilege escalation, data modification, or denial of service, the leakage of membership information could be sensitive in environments where organizational affiliations are confidential or where such information could be leveraged for targeted attacks. The requirement for authentication and knowledge of victim UUID limits the scope of exploitation, reducing the risk of widespread automated attacks. However, in large enterprises or service providers using Keycloak for identity and access management, this vulnerability could be exploited by insiders or compromised accounts to gather intelligence on other users. The absence of known exploits reduces immediate risk, but the vulnerability should be addressed promptly to prevent potential misuse.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 3 Apr 2026, 03:20 UTC

Technical details

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