CVE-2026-41005: UAA accepts SAML Encrypted Assertions authentication bypass
Cloud Foundry UAA incorrectly treated XML encryption to the Service Provider (confidentiality) as a substitute for XML signatures from the Identity Provider (authenticity) in two SAML flows: the OAuth 2.0 SAML2 bearer grant (token endpoint) and browser SSO (ACS) when wantAssertionSigned is set to false. Assertions or responses that were unsigned but contained encrypted content could still be accepted. Encryption uses the SP's public key from published metadata, therefore, any party, not only a trusted IdP, can produce ciphertext UAA can decrypt; successful decryption therefore does not prove the IdP issued the message.
Affected versions: Cloud Foundry UAA (uaarelease) 2.0.0 through 78.13.0. Cloud Foundry CF Deployment all versions through 56.1.0.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Configure UAA SAML to require signed assertions by setting wantAssertionSigned to true so unsigned (but encrypted) assertions/responses are not accepted.
Cloud Foundry UAA (SAML) wantAssertionSigned = true
Event History
Frequently Asked Questions
What is the severity of CVE-2026-41005?
The severity of CVE-2026-41005 is classified as critical with a score of 9.
How do I fix CVE-2026-41005?
To fix CVE-2026-41005, you should update to the latest version of Cloud Foundry UAA that addresses this vulnerability.
What systems are affected by CVE-2026-41005?
CVE-2026-41005 affects Cloud Foundry UAA and Cloud Foundry CF Deployment.
What is the risk associated with CVE-2026-41005?
CVE-2026-41005 poses a risk level of 78, indicating a significant potential for exploitation.
What type of vulnerability is CVE-2026-41005?
CVE-2026-41005 is an authentication bypass vulnerability related to SAML Encrypted Assertions.