Knative pkg contains a webhook admission handler that decodes incoming AdmissionReview requests without enforcing a maximum body size. An attacker who can reach the webhook can submit an oversized POST, causing the json decoder and a TeeReader buffer to grow unboundedly. This leads to rapid memory growth and eventually an out‑of‑memory kill of the controller pod, interrupting admission logic. The vulnerability corresponds to CWE‑770 and results in a denial‑of‑service condition for any product using the shared webhook implementation.

The affected component is knative.dev/pkg shared package. Versions earlier than 0.0.0-20260531000007-52dbd5ece63f are vulnerable. The issue propagates to downstream consumers that embed this webhook server, including Knative, Tekton, KEDA, Sigstore policy‑controller, and Kpack.

The CVSS score of 6.5 and the lack of evidence of an EPSS score indicate a moderate severity with currently unknown exploitation prevalence. The attack requires network access to the admission webhook endpoint, which is typically exposed within the cluster but may be restricted by network policies. Once a client can send a large payload, the local pod will be terminated, causing service disruption in all downstream workflows. The issue is not listed in the CISA KEV catalog, but entities relying on the vulnerable pkg should consider immediate remediation.