VulnerabilityPublished 23 Mar 2026Updated 22 Oct 2026

CVE-2026-4628: Red Hat Build of Keycloak · Improper Access Control

Affects Red Hat Build of KeycloakSource CVE Database V5

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Not known to be exploited · CVSS 4.3 Medium.

Data as of 29 Oct 2026, 19:15 UTC

CVSS 3.1 base score

4.3Medium

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

Thin evidence

One scorer or none

CVSS scores by source
CNA (redhat)	CVSS 3.1	4.3

EPSS: 0.2% chance of exploitation in 30 days – higher than 18% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: Low
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: 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: None: There is no loss of confidentiality within the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on 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 23 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 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

Affected software

Product	Affected	Fixed in
Red HatRed Hat build of Keycloak 26.4.12	Affected–	Fixed in–
Red Hat Build of Keycloakkeycloak-services	Affected–	Fixed in–
Red Hat JBoss Enterprise Application Platform 8keycloak-services	Affected–	Fixed in–
Red Hat JBoss Enterprise Application Platform Expansion Packkeycloak-services	Affected–	Fixed in–
Red Hat Single Sign-On 7keycloak-services	Affected–	Fixed in–

AI-suggested

To mitigate CVE-2026-4628, organizations should: 1) Apply any available patches or updates from Red Hat promptly once released. 2) Review and tighten access control policies around the UMA resource_set endpoint, ensuring that only trusted users have permission to modify resource sets. 3) Monitor logs for unusual PUT requests to the resource_set endpoint, especially from accounts with limited privileges. 4) Implement strong credential management and multi-factor authentication to reduce risk of credential compromise. 5) Consider temporarily disabling remote resource management features if not required. 6) Conduct regular audits of resource permissions and configurations within Keycloak to detect unauthorized changes early. 7) Educate administrators and developers on the importance of strict access control enforcement in identity management systems. These steps go beyond generic advice by focusing on the specific endpoint and feature affected, emphasizing proactive monitoring and configuration hardening.

Description

A flaw was found in Keycloak. An improper Access Control vulnerability in Keycloak’s User-Managed Access (UMA) resource_set endpoint allows attackers with valid credentials to bypass the allowRemoteResourceManagement=false restriction. This occurs due to incomplete enforcement of access control checks on PUT operations to the resource_set endpoint. This issue enables unauthorized modification of protected resources, impacting data integrity.

Impact

The primary impact of CVE-2026-4628 is unauthorized modification of protected resources within Keycloak's UMA framework, which can lead to data integrity issues. Organizations relying on Keycloak for identity and access management may face risks of privilege escalation or unauthorized access if attackers manipulate resource permissions. This can undermine trust in access controls and potentially expose sensitive systems or data indirectly. Since exploitation requires valid credentials, the threat is heightened in environments where credential compromise or insider threats exist. The vulnerability does not directly affect confidentiality or availability, limiting the scope of damage, but the integrity impact can have cascading effects on security policies and enforcement. Enterprises using Red Hat Build of Keycloak in critical authentication or authorization roles should consider this a moderate risk that could facilitate further attacks if left unmitigated.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 30 Mar 2026, 20:23 UTC

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