VulnerabilityPublished 11 Mar 2026Updated 2 Apr 2026

CVE-2026-3911: Red Hat build of Keycloak 26.4 · Exposure of Private Personal Information to an Unauthorized Actor

Affects Red Hat build of Keycloak 26.4Source CVE Database V5

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Not known to be exploited · CVSS 2.7 Low.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 3.1 base score

2.7Low

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:L/I:N/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: High
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: 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: 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 11 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	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

Organizations should immediately audit and restrict the assignment of the view-users role to only trusted administrators to minimize exposure. Monitoring and logging access to administrative endpoints should be enhanced to detect suspicious activity. As a proactive measure, consider implementing additional attribute-level access controls or custom filters within Keycloak to enforce stricter data visibility policies. Regularly review and update Keycloak configurations to ensure that sensitive attributes are not unnecessarily exposed. Employ multi-factor authentication for administrative accounts to reduce the risk of credential compromise. Finally, conduct periodic security assessments and penetration tests focusing on identity management components to identify similar weaknesses.

Description

A flaw was found in Keycloak. An authenticated user with the view-users role could exploit a vulnerability in the UserResource component. By accessing a specific administrative endpoint, this user could improperly retrieve user attributes that were configured to be hidden. This unauthorized information disclosure could expose sensitive user data.

Impact

The primary impact of CVE-2026-3911 is the unauthorized disclosure of sensitive user attributes that were configured to be hidden, potentially exposing private personal information. For organizations, this could lead to privacy violations, regulatory compliance issues (such as GDPR or CCPA), and erosion of user trust. Although the vulnerability requires authenticated access with the view-users role, insider threats or compromised accounts with this role could exploit the flaw. The exposure is limited to confidentiality and does not affect system integrity or availability, reducing the overall risk. However, in environments where Keycloak is used as a central identity provider for critical applications, even limited data leakage could facilitate further targeted attacks or social engineering. The lack of known exploits in the wild reduces immediate risk but does not eliminate the need for remediation.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 3 Apr 2026, 03:21 UTC

Technical details

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