CVE-2026-53717
Envoy Gateway: OCI layer extraction allocates make([]byte, h.Size) from untrusted tar header
Description
Vulnerability report without repro case. Repro case may be added later after harness is complete. **Preconditions (4):** - Tenant can create EnvoyExtensionPolicy (baseline) - Controller has egress to attacker-controlled OCI registry - No registry allowlist (none exists in code) - Layer presents Docker/OCI media type **Description** At imagefetcher.go:287, make([]byte, h.Size) uses the attacker-controlled tar-header size; the LimitReader at :278 bounds bytes read from the stream but not the header-declared size returned by tr.Next() (a 512-byte header can claim a multi-TB entry via PAX/GNU encoding). Reached from untrusted tenant input via EnvoyExtensionPolicy spec.wasm[].code.image.url (envoyextensionpolicy.go:1157 → cache.go:262/299 → imagefetcher.go:218 → :287), and the allocation happens for every tar entry regardless of filename. The resulting Go runtime OOM throw is unrecoverable and, because the CRD persists, crash-loops the shared controller — single-request, non-volumetric, cluster-wide DoS.
How to fix CVE-2026-53717
To remediate CVE-2026-53717, upgrade the affected package to a fixed version below.
- —upgrade to 1.8.1 or later
Is CVE-2026-53717 being exploited?
No exploitation signal available. Neither CISA KEV nor a current EPSS score has been published for CVE-2026-53717.
Affected packages (1)
- >= 1.8.0-rc.0, < 1.8.1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |