PatchSiren cyber security CVE debrief

CVE-2026-41005 Cloud Foundry CVE debrief

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.

Vendor: Cloud Foundry
Product: UAA
CVSS: CRITICAL 9
CISA KEV: Not listed in stored evidence
Original CVE published: 2026-06-11
Original CVE updated: 2026-06-12
Advisory published: 2026-06-11
Advisory updated: 2026-06-12

Who should care

Users of Cloud Foundry UAA (uaa_release) 2.0.0 through 78.13.0 and Cloud Foundry CF Deployment all versions through 56.1.0.

Technical summary

The vulnerability allows for an authentication bypass due to incorrect handling of SAML encryption and signatures. Specifically, the UAA would accept unsigned SAML assertions or responses if they were encrypted, using the Service Provider's public key for decryption. This means any party can create encrypted content that the UAA can decrypt, without proving the Identity Provider issued the message.

Defensive priority

CRITICAL

Recommended defensive actions

Upgrade to Cloud Foundry UAA (uaa_release) version 78.13.1 or later.
Upgrade to Cloud Foundry CF Deployment version 56.1.1 or later.

Evidence notes

CVE-2026-41005 has been assessed as CRITICAL with a CVSS score of 9. Affected versions include Cloud Foundry UAA (uaa_release) 2.0.0 through 78.13.0 and Cloud Foundry CF Deployment all versions through 56.1.0.

Official resources

CVE-2026-41005 was published on 2026-06-11T21:16:21.807Z and modified on 2026-06-12T16:06:17.027Z.