Medium

CVE-2026-53716 — Envoy Gateway: Wasm HTTP fetch decompresses gzip without output-size limit

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.

Published Sep 14, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: GitHub_M

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.7% (30-day exploitation probability)+8
Technical severity (medium)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.72%

ahead of 53% of scored CVEs · Oct 15, 2026

Affects

Envoyproxy

Gateway

CVSS base

6.5

Medium · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Envoyproxy Gateway).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Envoyproxy	Gateway	version < 1.7.4version >= 1.8.0-rc.0, < 1.8.1	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

Low

Privileges required

Low

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
6.5	CVSS 3.1	Medium	2.8	3.6	security-advisories@github.com via NIST National Vulnerability Database
6.5	CVSS 3.1	Medium	—	—	GitHub_M via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H (score shown at the top: security-advisories@github.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-789

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).

web/proxy/WAF logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first.

2026
Affected products added · envoyproxy/gateway
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 15, 2026
CVSS changed · 6.5
Oct 15, 2026 · NIST National Vulnerability Database
Source status changed · → Awaiting Analysis
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
CVE published
Sep 14, 2026 · GitHub_M

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

9 on the record

github.com/envoyproxy/gateway/commit/96e2b750868a459ace4b8b68e6a6e4fb0152b9b7
x_refsource_MISC, NIST National Vulnerability Database
github.com/envoyproxy/gateway/commit/b4737180c7e597490c6363075c565fa8cf24eead
x_refsource_MISC, NIST National Vulnerability Database
github.com/envoyproxy/gateway/releases/tag/v1.7.4
x_refsource_MISC, NIST National Vulnerability Database
github.com/envoyproxy/gateway/security/advisories/GHSA-cxpq-8v7q-cg56
x_refsource_CONFIRM, NIST National Vulnerability Database
github.com/envoyproxy/gateway/commit/5a78db82b7cf4fc5bebbeda2c50952892038a464
x_refsource_MISC, NIST National Vulnerability Database
github.com/envoyproxy/gateway/releases/tag/v1.8.1
x_refsource_MISC, NIST National Vulnerability Database
github.com/envoyproxy/gateway/pull/9171
x_refsource_MISC, NIST National Vulnerability Database
github.com/envoyproxy/gateway/pull/9172
x_refsource_MISC, NIST National Vulnerability Database
github.com/envoyproxy/gateway/pull/9173
x_refsource_MISC, NIST National Vulnerability Database

Elsewhere on this site

Envoyproxy
every CVE for this vendor

CWE-789
other pages naming this weakness

Related CVEs (same products)

Medium CVE-2026-53718 Envoy Gateway custom backendRef cross-namespace ReferenceGrant bypass Sep 14, 2026
Medium CVE-2026-53719 Envoy Gateway: Nil-dereference when SecurityPolicy targets TCPRoute without spec.authorization Sep 14, 2026
Critical CVE-2026-53713 Envoy Gateway: Authentication Bypass via Improper Input Validation in EnvoyExtensionPolicy Lua Allows Secret Disclosure Sep 14, 2026
High CVE-2026-53714 Envoy Gateway: xDS Control Plane Information Disclosure when Envoy Gateway operates in GatewayNamespaceMode Sep 14, 2026
Medium CVE-2026-53715 Envoy Gateway: Wasm cache ServeHTTP reads mappingPath2Cache without lock Sep 14, 2026
Medium CVE-2026-53717 Envoy Gateway: OCI layer extraction allocates make([]byte, h.Size) from untrusted tar header Sep 14, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No fixed version, patch or mitigation documented.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-53716 is "Envoy Gateway: Wasm HTTP fetch decompresses gzip without output-size limit", rated Medium. It affects Gateway (Envoyproxy); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 6.5 describes technical severity. EPSS 0.72% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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