The HTTP/2 protocol allows a denial of service (server resource consumption) because request cancellation can reset many streams quickly, as exploited in the wild in August through October 2023.

A flaw was found in Undertow, which incorrectly parses cookies with certain value-delimiting characters in incoming requests. This issue could allow an attacker to construct a cookie value to exfiltrate HttpOnly cookie values or spoof arbitrary additional cookie values, leading to unauthorized data access or modification. The main threat from this flaw impacts data confidentiality and integrity.

A flaw was found in hibernate-validator's 'isValid' method in the org.hibernate.validator.internal.constraintvalidators.hv.SafeHtmlValidator class, which can be bypassed by omitting the tag ending in a less-than character. Browsers may render an invalid html, allowing HTML injection or Cross-Site-Scripting (XSS) attacks.

A flaw was found in the SAML client registration in Keycloak that could allow an administrator to register malicious JavaScript URIs as Assertion Consumer Service POST Binding URLs (ACS), posing a Cross-Site Scripting (XSS) risk. This issue may allow a malicious admin in one realm or a client with registration access to target users in different realms or applications, executing arbitrary JavaScript in their contexts upon form submission. This can enable unauthorized access and harmful actions, compromising the confidentiality, integrity, and availability of the complete KC instance.

A flaw was found in Keycloak's OIDC component in the "checkLoginIframe," which allows unvalidated cross-origin messages. This flaw allows attackers to coordinate and send millions of requests in seconds using simple code, significantly impacting the application's availability without proper origin validation for incoming messages.

A flaw was found in Keycloak, where it does not properly validate URLs included in a redirect. This issue could allow an attacker to construct a malicious request to bypass validation and access other URLs and sensitive information within the domain or conduct further attacks. This flaw affects any client that utilizes a wildcard in the Valid Redirect URIs field, and requires user interaction within the malicious URL.