GHSA-cxpq-8v7q-cg56 Envoy Gateway: Wasm HTTP fetch decompresses gzip without output-size limit

• Go github.com/envoyproxy/gateway: >= 1.8.0-rc.0, < 1.8.1 → fixed in 1.8.1 • Go github.com/envoyproxy/gateway: < 1.7.4 → fixed in 1.7.4

Vulnerability report without repro case. Repro case may be added later after harness is complete. Preconditions (4): • Tenant can create EnvoyExtensionPolicy (baseline) • Attacker hosts a gzip-bomb at a reachable URL • sha256 unset (optional field; check is post-decompression anyway) • No operator Wasm-URL allowlist (none exists in code) Description getFileFromGZ calls io.ReadAll on a raw gzip.Reader (httpfetcher.go:216) with no output bound, while the compressed input is capped at 256 MiB (httpfetcher.go:139). The bytes originate from a tenant-controlled EnvoyExtensionPolicy.spec.wasm[].code.http.url (envoyextensionpolicy.go:1077 → cache.go:248 → httpfetcher.go:147 → :233), so an untrusted tenant can point at a ~10 MiB gzip-of-zeros and force ~10 GiB allocation in the shared controller process. All candidate guards execute either before the body is buffered or after decompression. OOM-kills, restarts, re-reconciles same CR, crash-loops — persistent cross-tenant control-plane outage with PR:L/AC:L and scope change → HIGH despite availability-only.