notion-go is a collection of libraries for supporting sign and verify OCI artifacts. Based on Notary Project specifications. This issue was identified during Quarkslab's audit of the timestamp feature. During the timestamp signature generation, the revocation status of the certificate(s) used to generate the timestamp signature was not verified. During timestamp signature generation, notation-go did not check the revocation status of the certificate chain used by the TSA. This oversight creates a vulnerability that could be exploited through a Man-in-The-Middle attack. An attacker could potentially use a compromised, intermediate, or revoked leaf certificate to generate a malicious countersignature, which would then be accepted and stored by notation. This could lead to denial of service…