Constellation is the first Confidential Kubernetes. The Constellation CVM image uses LUKS2-encrypted volumes for persistent storage. When opening an encrypted storage device, the CVM uses the libcryptsetup function crypt_activate_by_passhrase.
If the VM is successful in opening the partition with the disk encryption key, it treats the volume as confidential. However, due to the unsafe handling of null keyslot algorithms in the cryptsetup 2.8.1, it is possible that the opened volume is not encrypted at all. Cryptsetup prior to version 2.8.1 does not report an error when processing LUKS2-formatted disks that use the cipher_null-ecb algorithm in the keyslot encryption field.
This vulnerability is fixed in 2.24.0.
Attack Parameters
Attack Vector
Local
Requires local access
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
High
Admin privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
None
No disruption
CVSS Vector v4.0
Weakness Type (CWE)
Vulnerable Products
edgelesssys:constellation
References 4
https://github.com/edgelesssys/constellation/pull/3927
security-advisories@github.com
https://github.com/edgelesssys/constellation/releases/tag/v2.24.0
security-advisories@github.com
https://github.com/edgelesssys/constellation/security/advisories/GHSA-hq76-6gh2…
security-advisories@github.com
https://blog.trailofbits.com/2025/10/30/vulnerabilities-in-luks2-disk-encryptio…
af854a3a-2127-422b-91ae-364da2661108