CVE-2026-22723: Cloudfoundry UAA Auth Bypass Vulnerability

CVE-2026-22723 Overview

CVE-2026-22723 is a business logic vulnerability affecting the token revocation endpoint in Cloud Foundry UAA (User Account and Authentication). The flaw stems from a logic error in the token revocation implementation that prevents proper invalidation of user tokens, potentially allowing revoked tokens to remain valid and usable after revocation attempts.

Critical Impact

Authenticated attackers can exploit this vulnerability to maintain persistent access through tokens that should have been revoked, potentially leading to denial of service conditions for legitimate token management operations.

Affected Products

• Cloud Foundry UAA v77.30.0 to v78.7.0
• Cloud Foundry Deployment v48.7.0 to v54.10.0

Discovery Timeline

• 2026-03-05 - CVE CVE-2026-22723 published to NVD
• 2026-03-05 - Last updated in NVD database

Technical Details for CVE-2026-22723

Vulnerability Analysis

This vulnerability represents a business logic flaw in the Cloud Foundry UAA token revocation endpoint. When administrators or users attempt to revoke OAuth2 tokens through the designated API endpoint, the underlying implementation fails to properly invalidate the targeted tokens due to an error in the revocation logic.

The flaw allows authenticated users with low privileges to exploit the improper token revocation mechanism. Since the token revocation process does not function as intended, previously issued tokens may continue to be accepted by the system even after explicit revocation requests. This creates a scenario where session management and access control can be circumvented.

The network-accessible nature of this vulnerability means that any authenticated user can potentially trigger the condition remotely without requiring any user interaction. The primary impact is on system availability, as the broken revocation mechanism undermines the integrity of the authentication infrastructure.

Root Cause

The root cause lies in a logic error within the token revocation endpoint implementation. The UAA component fails to properly validate and execute token invalidation requests, likely due to incorrect conditional logic, missing state updates in the token store, or improper handling of the revocation request parameters. This results in tokens remaining in a valid state despite revocation attempts.

Attack Vector

An attacker with valid low-privilege credentials can exploit this vulnerability by:

1. Authenticating to the Cloud Foundry UAA service and obtaining a valid OAuth2 token
2. Performing actions that would typically trigger token revocation (password change, logout, explicit revocation request)
3. Continuing to use the "revoked" token for authentication, as the revocation logic fails to properly invalidate it

This attack requires network access and valid authentication credentials but does not require elevated privileges or user interaction. The vulnerability could be leveraged to maintain persistent access to Cloud Foundry resources or to disrupt legitimate token lifecycle management operations.

Detection Methods for CVE-2026-22723

Indicators of Compromise

• OAuth2 tokens being accepted after explicit revocation requests have been issued
• Anomalous authentication patterns where tokens remain valid beyond expected session lifetimes
• Multiple active sessions for users who should have been logged out through token revocation

Detection Strategies

• Monitor UAA audit logs for token revocation requests and correlate with subsequent authentication attempts using the same tokens
• Implement token validation checks that verify revocation status against the token store
• Deploy network monitoring to identify authentication requests using tokens that were previously flagged for revocation

Monitoring Recommendations

• Enable detailed logging on the UAA token revocation endpoint to capture all revocation requests and their outcomes
• Set up alerts for authentication events that occur after corresponding token revocation events
• Regularly audit token lifecycle events to ensure revocation operations are completing successfully

How to Mitigate CVE-2026-22723

Immediate Actions Required

• Upgrade Cloud Foundry UAA to a version outside the affected range (v77.30.0 to v78.7.0)
• Upgrade Cloud Foundry Deployment to a version outside the affected range (v48.7.0 to v54.10.0)
• Review and audit active tokens in your environment, especially for privileged accounts
• Consider implementing additional token validation layers at the application level

Patch Information

Cloud Foundry has released security updates addressing this vulnerability. Organizations should upgrade to patched versions as documented in the Cloud Foundry security advisory. Consult the official Cloud Foundry release notes for specific version guidance and upgrade procedures.

Workarounds

• Implement shorter token expiration times to reduce the window of exposure for tokens that fail to revoke
• Deploy additional authentication middleware that independently validates token status
• Enable enhanced audit logging to manually track and invalidate problematic tokens
• Consider implementing a token denylist at the application layer as a defense-in-depth measure

# Example: Reducing token validity period in UAA configuration
# uaa.yml configuration adjustment
uaa:
  token:
    policy:
      accessTokenValiditySeconds: 600
      refreshTokenValiditySeconds: 1800