CVE-2026-53716: Envoy Gateway Wasm HTTP Fetch Decompresses Gzip Vulnerability

MODERATE
Advisory Identifier: GHSA-cxpq-8v7q-cg56
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CVSS 6.5
CWE-789
Published
Advisory Summary

CVE-2026-53716 is a MODERATE (CVSS 6.5) wasm http fetch decompresses gzip vulnerability (CWE-789: Memory Allocation with Excessive Size Value) affecting Envoy Gateway libraries in the Go ecosystem. The issue involves wasm http fetch decompresses gzip without output-size limit. Remediation is available by upgrading affected packages to version 1.8.1, 1.7.4.

CVE-2026-53716 at a Glance

CVE Identifier CVE-2026-53716
GHSA Identifier GHSA-cxpq-8v7q-cg56
Severity MODERATE
CVSS v3.1 Base Score 6.5
CWE Classification CWE-789: Memory Allocation with Excessive Size Value
Affected Product Envoy Gateway
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 6.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2026-53716

To remediate this vulnerability, upgrade all affected Envoy Gateway dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

github.com/envoyproxy/gateway fixed: 1.8.1 
Upgrade github.com/envoyproxy/gateway to 1.8.1
github.com/envoyproxy/gateway fixed: 1.7.4 
Upgrade github.com/envoyproxy/gateway to 1.7.4
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for github.com/envoyproxy/gateway

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-53716, inspect your project dependencies for Envoy Gateway:

inspect dependencies for github.com/envoyproxy/gateway

Analyze the terminal output to locate any version of Envoy Gateway in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.8.1), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-789: Memory Allocation with Excessive Size Value, where the product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated. In Envoy Gateway, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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.

CVE-2026-53716 Affected Envoy Gateway Versions

2 component(s)
Fixed Versions:
1.8.11.7.4
Product / Package Ecosystem Affected Versions Fixed Version
github.com/envoyproxy/gateway
golang/github.com/envoyproxy/gateway
Go
≥ 1.8.0-rc.0
< 1.8.1
1.8.1
github.com/envoyproxy/gateway
golang/github.com/envoyproxy/gateway
Go
< 1.7.4
1.7.4

References

GitHub Advisory / Wiki ADVISORY
https://github.com/envoyproxy/gateway/security/advisories/GHSA-cxpq-8v7q-cg56
Envoy Gateway Source Repository REPOSITORY
https://github.com/envoyproxy/gateway

Frequently Asked Questions

What is CVE-2026-53716?
CVE-2026-53716 is a security vulnerability in Envoy Gateway involving Wasm HTTP fetch decompresses gzip without output-size limit under CWE-789: Memory Allocation with Excessive Size Value.
Which Envoy Gateway versions are affected?
Affected versions include releases prior to 1.8.1, 1.7.4 across affected packages: github.com/envoyproxy/gateway.
What version fixes CVE-2026-53716?
Upgrading to 1.8.1, 1.7.4 (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/envoyproxy/gateway affected?
Yes, github.com/envoyproxy/gateway is affected in releases prior to 1.8.1, 1.7.4. Upgrade your dependency to 1.8.1, 1.7.4 or later.
What is the CVSS score of CVE-2026-53716?
CVE-2026-53716 has a CVSS v3.1 base score of 6.5 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2026-53716?
CVE-2026-53716 is classified under CWE-789: Memory Allocation with Excessive Size Value (The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated.).
How can I check Go dependencies for CVE-2026-53716?
Run the dependency tree command: 'inspect dependencies for github.com/envoyproxy/gateway'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-cxpq-8v7q-cg56",
  "modified" : "2026-07-16T19:18:08Z",
  "published" : "2026-07-16T19:18:08Z",
  "aliases" : [ "CVE-2026-53716" ],
  "summary" : "Envoy Gateway: Wasm HTTP fetch decompresses gzip without output-size limit",
  "details" : "Vulnerability report without repro case. Repro case may be added later after harness is complete.\n\n**Preconditions (4):**\n- Tenant can create EnvoyExtensionPolicy (baseline)\n- Attacker hosts a gzip-bomb at a reachable URL\n- sha256 unset (optional field; check is post-decompression anyway)\n- No operator Wasm-URL allowlist (none exists in code)\n\n**Description**\n\ngetFileFromGZ 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.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/envoyproxy/gateway"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.8.0-rc.0"
      }, {
        "fixed" : "1.8.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/envoyproxy/gateway"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.7.4"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/envoyproxy/gateway/security/advisories/GHSA-cxpq-8v7q-cg56"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/envoyproxy/gateway"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-789" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-16T19:18:08Z",
    "nvd_published_at" : null
  }
}