CVE-2026-68745 Overview
CVE-2026-68745 is a certificate validation failure in the Security Assertion Markup Language (SAML) authentication flow of Apache CloudStack versions 4.20.3.0 and 4.22.1.0. The management server fails to properly validate signatures on SAML responses, allowing an attacker to forge assertions and authenticate as an arbitrary user. Exploitation requires the attacker to either spoof the Identity Provider (IdP) IP address or register an attacker-controlled URL as a trusted IdP endpoint in the management server. Once either precondition is met, forged signatures are accepted and login proceeds. The weakness maps to [CWE-347: Improper Verification of Cryptographic Signature].
Critical Impact
Successful exploitation grants attacker-controlled authentication to the CloudStack management server, exposing full cloud orchestration control across compute, storage, and network resources.
Affected Products
- Apache CloudStack 4.20.3.0
- Apache CloudStack 4.22.1.0
- Fixed in Apache CloudStack 4.20.3.1 and 4.22.1.1 and later
Discovery Timeline
- 2026-08-21 - CVE-2026-68745 published to NVD
- 2026-08-27 - Last updated in NVD database
Technical Details for CVE-2026-68745
Vulnerability Analysis
Apache CloudStack supports SAML-based single sign-on (SSO) to the management server. In a correct SAML flow, the Service Provider (SP) validates the digital signature on the assertion using the IdP's registered public certificate. This binding ensures that only the legitimate IdP can issue authentication statements.
In the affected releases, the SAML response handler does not enforce certificate validation correctly. An attacker who submits a crafted SAML response can pass the authentication check despite the response being signed with an unauthorized key. The management server treats the forged assertion as valid and issues an authenticated session.
Root Cause
The root cause is improper verification of the cryptographic signature on inbound SAML responses [CWE-347]. Trust anchors bound to the registered IdP are not correctly evaluated against the signing material presented in the response, so signatures from attacker-controlled keys are accepted.
Attack Vector
Exploitation occurs over the network without authentication or user interaction, but attack complexity is high because the attacker must satisfy one of two preconditions. The first path requires spoofing the IP address of the trusted IdP so responses appear to originate from a legitimate source. The second path requires registering an attacker-chosen URL in the management server as an IdP endpoint, which typically implies prior administrative access or a separate misconfiguration. Once either condition holds, the attacker submits a SAML response with a forged signature and receives an authenticated session for the targeted user.
No public proof-of-concept is available, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.
Detection Methods for CVE-2026-68745
Indicators of Compromise
- SAML authentication events in CloudStack logs signed by certificates or key identifiers that do not match the registered IdP metadata.
- New or modified IdP endpoint URLs in the management server configuration, particularly pointing to external or non-corporate domains.
- Successful SAML logins originating from source IP addresses that do not correspond to the legitimate IdP's network range.
Detection Strategies
- Enable verbose logging on the CloudStack management server SAML plugin and inspect signature validation outcomes for anomalies.
- Compare inbound SAML response issuer values and signing certificate thumbprints against the expected IdP metadata baseline.
- Correlate CloudStack administrative logins with corresponding IdP-side authentication events; missing IdP-side records indicate forged assertions.
Monitoring Recommendations
- Alert on any change to the samlIdentityProvider or IdP metadata URL configuration in the management server database.
- Monitor for ARP spoofing, BGP anomalies, or DNS changes on network paths between the management server and the IdP.
- Track privileged CloudStack account logins and flag sessions originating from unexpected geographies or ASNs.
How to Mitigate CVE-2026-68745
Immediate Actions Required
- Upgrade Apache CloudStack to version 4.20.3.1, 4.22.1.1, or later, which contain the signature validation fix.
- Audit the management server configuration for unauthorized IdP endpoints and remove any entries that were not explicitly provisioned.
- Rotate any administrative credentials or API keys that may have been exposed if forged SAML logins are suspected.
Patch Information
The Apache CloudStack project addressed CVE-2026-68745 in releases 4.20.3.1 and 4.22.1.1. Upgrade details and the security announcement are available in the Apache Mailing List Thread.
Workarounds
- Disable the SAML authentication plugin on the management server until the patched version is deployed, and rely on local or LDAP authentication.
- Restrict network access to the management server so that SAML responses can only be received from the legitimate IdP source addresses.
- Enforce mutual TLS or IPsec between the management server and the IdP to prevent IP spoofing on the SAML callback path.
# Configuration example: disable SAML auth plugin in CloudStack global settings
# then restart the management server to apply
mysql -u cloud -p cloud -e \
"UPDATE configuration SET value='false' WHERE name='saml2.enabled';"
systemctl restart cloudstack-management
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
