VulnerabilityPublished 6 Oct 2026Updated 6 Nov 2026

CVE-2026-105305: Improper Authentication

Source GCVE Database

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Authoritative record:CVE-2026-105305· Medium 5.4

Not known to be exploited · CVSS 5.4 Medium : update Red Hat build of Keycloak 26.6.8 when convenient.

Data as of 6 Nov 2026, 13:50 UTC

CVSS 3.1 base score

5.4Medium

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	5.4

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: Low
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: 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: 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 6 Oct 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 6 Nov 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.

ghsa-ggxp-hq23-v84f

What to do

Patches and advisories

access.redhat.com/errata/RHSA-2026:95761 (opens in a new tab)

Affected software

Product	Affected	Fixed in
Red Hat build of Keycloak 26.6.8keycloak-services	Affected–	Fixed in–
Red Hat build of Keycloak 26.6.8rhbk/keycloak-rhel9	Affected–	Fixed in–
Red Hat Single Sign-On 7keycloak-services	Affected–	Fixed in–

AI-suggested

A security update is available in Red Hat build of Keycloak version 26.6.8 that fixes this vulnerability. Users should apply this official patch promptly to remediate the issue. No alternative mitigations or workarounds are indicated in the vendor advisory.

Description

A vulnerability in the OpenID Connect (OIDC) Device Authorization Grant flow of Keycloak allows attackers who have stolen a user's password to bypass mandatory multi-factor authentication (MFA). This flaw occurs because the flow does not enforce the minimum authentication level configured by the client, enabling unauthorized access to the Keycloak Admin REST API.

Impact

An attacker with a stolen user password can bypass mandatory multi-factor authentication protections, potentially gaining unauthorized access to the Keycloak Admin REST API. This could lead to unauthorized administrative actions within the Keycloak server environment. The CVSS v3.1 base score is 5.4 (medium severity), reflecting limited scope and complexity but significant impact on confidentiality and integrity.

Summary

CVE-2026-105305 is a vulnerability in Keycloak's OIDC implementation, specifically in the Device Authorization Grant flow designed for devices with limited input capabilities. The flaw arises from a failure to verify the minimum authentication context class reference (acr) value required by client configuration. Consequently, an attacker possessing a user's password can circumvent enforced multi-factor authentication and gain unauthorized administrative access via the Keycloak Admin REST API. This issue is addressed in Red Hat build of Keycloak version 26.6.8 as part of a security update.

CWE-287Improper Authentication (opens in a new tab)
Class weaknessLikelihood of exploit: HighOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design · Libraries or Frameworks
Use an authentication framework or library such as the OWASP ESAPI Authentication feature.
OWASP Cheat Sheets
OWASP Authentication (opens in a new tab)
OWASP ASVS 4.0.3
V2.8.5 (opens in a new tab)
V2.8.4 (opens in a new tab)
V9.2.3 (opens in a new tab)
Attack patterns
Fake the Source of Data (opens in a new tab)
Utilizing REST's Trust in the System Resource to Obtain Sensitive Data (opens in a new tab)
Session Hijacking (opens in a new tab)
Token Impersonation (opens in a new tab)
Upload a Web Shell to a Web Server (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Patches and advisories

Affected software

Description

AI analysisMachine-generated, updated 6 Nov 2026, 13:50 UTC

WeaknessesCWE-287

Technical details

References

Community reviews

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