VulnerabilityPublished 27 Feb 2026Updated 6 Mar 2026

CVE-2026-0871: Red Hat build of Keycloak 26.4 · Incorrect Privilege Assignment

Affects Red Hat build of Keycloak 26.4Source CVE Database V5

Compare

Not known to be exploited · CVSS 4.9 Medium.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score

4.9Medium

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

EPSS: 0.3% chance of exploitation in 30 days – higher than 28% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: High
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: High
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: None: There is no loss of confidentiality within the impacted component.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to 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 27 Feb 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
Mavenorg.keycloak/keycloak`pkg:maven/org.keycloak/keycloak`Other threats	Affected =26.4	Fixed in–

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

AI-suggested

To mitigate CVE-2026-0871, organizations should: 1) Monitor Red Hat and Keycloak official channels for patches or updates addressing this vulnerability and apply them promptly once available. 2) Review and tighten administrative permissions, ensuring that only trusted personnel have 'manage-users' privileges, minimizing the risk of misuse. 3) Implement strict auditing and logging of administrative actions related to user profile modifications to detect unauthorized changes quickly. 4) Consider segregating duties by limiting the scope of administrators who can manage user attributes, especially unmanaged ones. 5) Use Keycloak's built-in policies or custom extensions to enforce additional attribute-level access controls if feasible. 6) Conduct regular security reviews and penetration tests focusing on identity and access management configurations. 7) Educate administrators about the risks of privilege misuse and enforce strong authentication methods to protect admin accounts. These steps go beyond generic advice by focusing on permission hygiene, monitoring, and compensating controls until patches are applied.

Description

A flaw was found in Keycloak. An administrator with `manage-users` permission can bypass the "Only administrators can view" setting for unmanaged attributes, allowing them to modify these attributes. This improper access control can lead to unauthorized changes to user profiles, even when the system is configured to restrict such modifications.

Impact

The primary impact of CVE-2026-0871 is on the integrity of user profile data within Keycloak-managed environments. Unauthorized modification of unmanaged attributes by administrators with 'manage-users' permission can undermine trust in identity data, potentially enabling privilege escalation or unauthorized access if these attributes influence access control decisions. Organizations relying on Keycloak for critical authentication and authorization services may face risks of identity spoofing or policy circumvention. Although confidentiality and availability are not directly affected, the integrity compromise can have cascading effects on security posture, compliance, and auditability. The requirement for administrative privileges limits the attack surface to insider threats or compromised admin accounts. However, given Keycloak's widespread use in enterprise, cloud, and government sectors, the vulnerability could have broad implications if exploited. No active exploitation reduces immediate risk but does not eliminate the need for prompt remediation.

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 6 Mar 2026, 20:35 UTC

Technical details

References

Community reviews

Related threats