VulnerabilityPublished 16 Sep 2026Updated 18 Sep 2026

CVE-2026-74909: Red Hat build of Keycloak 26.4 · Missing Authorization

Affects Red Hat build of Keycloak 26.4Source CVE Database V5

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Mentioned vulnerabilities

CVE-2026-15573

Not known to be exploited · CVSS 8.1 High.

Data as of 31 Oct 2026, 20:20 UTC

CVSS 3.1 base score

8.1High

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

EPSS: 0.8% chance of exploitation in 30 days – higher than 58% 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:H/I:H/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: High
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: 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: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
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 16 Sep 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 31 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.

cwe-862

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 26.4.16	Affected–	Fixed in–
Red HatRed Hat build of Keycloak 26.6	Affected–	Fixed in–
Red HatRed Hat build of Keycloak 26.6	Affected–	Fixed in–
Red HatRed Hat build of Keycloak 26.6.7	Affected–	Fixed in–

AI-suggested

As per the Red Hat advisory, no effective mitigation is currently available that meets their criteria for ease of use, deployment, and applicability. Red Hat has released updated Keycloak 26.4.16 container images for OpenShift that address this vulnerability as part of a broader security update. Users are advised to upgrade to these fixed versions. Before updating, back up existing installations including configurations and databases. Customers should monitor Red Hat advisories for further updates and coordinate with Red Hat support or Technical Account Managers if needed.

Description

Keycloak provides a policy enforcer to protect applications by matching incoming web requests against defined security policies. A flaw was found where the enforcer fails to correctly normalize web addresses that contain special encoded characters, such as those representing semicolons or directory traversal segments. An authenticated user can use these encoded characters to trick the enforcer into applying a less restrictive security policy than intended, potentially gaining unauthorized access to sensitive administrative or private application endpoints.

Impact

Successful exploitation allows an authenticated attacker to bypass authorization controls and gain unauthorized access to sensitive administrative or private endpoints within Keycloak-protected applications. This can lead to unauthorized reading and modification of sensitive data and potentially privilege escalation. The vulnerability does not impact availability. Red Hat rates the severity as Important (high) with a CVSS 3.1 score of 8.1, reflecting high confidentiality and integrity impacts with low attack complexity and low privileges required.

Summary

Keycloak's policy enforcer component, which protects applications by matching incoming web requests against security policies, does not properly normalize URIs containing special encoded characters such as semicolons or directory traversal sequences. An authenticated attacker can exploit this to bypass authorization checks and access restricted endpoints. This vulnerability stems from an incomplete fix for a prior URI normalization flaw (CVE-2026-15573). Red Hat's advisory confirms the issue affects their build of Keycloak 26.4 and classifies the severity as Important with a CVSS 3.1 score of 8.1. The vulnerability allows privilege escalation by bypassing authorization controls, impacting confidentiality and integrity of data and application functionality.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 24 Sep 2026, 04:36 UTC

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