A security vulnerability was found in Kyverno where an attacker could cause denial of service of Kyverno. The vulnerable component in Kyvernos Notary verifier. An attacker would need control over the registry from which Kyverno would fetch attestations. With such a position, the attacker could return a malicious response to Kyverno, when Kyverno would send a request to the registry. The malicious response would cause denial of service of Kyverno, such that other users' admission requests would be blocked from being processed.

This is a vulnerability in a new component released in v1.11.0. The only users affected by this are those that have been building Kyverno from source at the main branch which is not encouraged. Users consuming official Kyverno releases are not affected. There are no known cases of this vulnerability being exploited in the wild.

The vulnerability was found during an ongoing security audit of Kyverno conducted by Ada Logics, facilitated by OSTIF and funded by the CNCF.

References:
https://github.com/kyverno/kyverno/security/advisories/GHSA-wc3x-5rfv-hh5v