Bug 2539280 (CVE-2026-96445)

Summary: CVE-2026-96445 keycloak-services: keycloak-services: Conditional OTP skip-header policy evaluated against untrusted proxy headers
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: aschwart, aszczucz, boliveir, drichtar, mposolda, pjindal, rmartinc, ssilvert, sthorger, vmuzikar
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Conditional OTP authenticator of Keycloak, an identity and access management solution. The issue occurs when the system evaluates specific HTTP headers to determine if a one-time password (OTP) should be skipped, but fails to verify if those headers came from a trusted source. This could allow an attacker who already has a user's password to bypass the second-factor authentication by providing a specially crafted header in their request.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-09-23 09:31:18 UTC 
A flaw was found in the ConditionalOtpFormAuthenticator component of Keycloak. The vulnerability exists because the skip-header policy evaluates configured header patterns against raw request headers without verifying whether the request originates from a trusted proxy via the isProxyTrusted check.
Exploitation requires that the target realm has a Conditional OTP flow configured with a skip rule for a specific HTTP header and that the attacker has already obtained a victim's password. By injecting the matching header directly into the login request, an attacker can cause Keycloak to treat the request as if it came from a trusted environment where OTP is not required. Successful exploitation allows an attacker to bypass multi-factor authentication, gain full access to the victim's account, modify user data, and perform administrative actions if the victim has elevated privileges.