CVE-2026-53716

Envoy Gateway: Wasm HTTP fetch decompresses gzip without output-size limit

MEDIUM
6.5
CVSS Score
Published: September 14, 2026 at 08:15 PM UTC
Updated: September 30, 2026 at 05:43 PM UTC
1 product affected across 1 vendorGateway

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Severity
MEDIUM6.5
Exploit prediction
EPSS 0.7%
SSVC
No known exploit

Description

Envoy Gateway is an open source project for managing Envoy Proxy as a standalone or Kubernetes-based application gateway. Prior to 1.7.4 and 1.8.1, getFileFromGZ in internal/wasm/httpfetcher.go calls io.ReadAll on a gzip.Reader without limiting decompressed output when a tenant-controlled EnvoyExtensionPolicy.spec.wasm[].code.http.url points to a reachable compressed Wasm payload. The 256 MiB compressed-input cap does not constrain the expanded size, no operator Wasm URL allowlist exists, and the optional sha256 check occurs only after decompression, so a comparatively small gzip stream can force a multi-gigabyte allocation in the shared controller. The resulting out-of-memory termination restarts the controller, re-reconciles the persistent custom resource, and can create a persistent cross-tenant control-plane outage. This issue is fixed in versions 1.7.4 and 1.8.1.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.7.4v < 1.8.1
Affected range stops below 1.7.4, so it looks safe — our inference, not a vendor statement
Affected range stops below 1.8.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.5MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusAWAITING ANALYSIS
CWE
CWE-789

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