CVE-2026-54725: vault-addr annotation SSRF -- webhook makes outbound HTTP call to attacker URL during admission; vault-serviceaccount enables cluster-wide SA token theft via TokenRequest API

The vault-secrets-webhook reads the vault.security.banzaicloud.io/vault-addr annotation from any ConfigMap or Secret being admitted and uses it as the Vault server address without any validation or allowlist. When a ConfigMap or Secret contains a value prefixed with vault:, the webhook’s admission handler synchronously calls the Vault API at the attacker-supplied address from inside the webhook process during the admission review. The webhook additionally grants serviceaccounts/token:create cluster-wide, and the vault-serviceaccount annotation controls which ServiceAccount’s JWT is fetched and sent to that address. An attacker who can create ConfigMaps or Secrets in a watched namespace can cause the webhook process to make arbitrary outbound HTTP connections and exfiltrate ServiceAccount JWTs.