CyberSecBulletin
CVE-2026-53713NVD status: Awaiting Analysis

Envoy Gateway is an open source project for managing Envoy Proxy as a standalone or…

Published Updated By the CyberSecBulletin desk

CVE-2026-53713 is a critical-severity improper input validation vulnerability in gateway from Envoyproxy, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected gateway versions: < 1.7.4; >= 1.8.0-rc.0, < 1.8.1. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.43% chance of exploitation within 30 days, which is low compared with other CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of gateway you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
Envoyproxygateway< 1.7.4; >= 1.8.0-rc.0, < 1.8.1Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
HighAll data handled by the component can be read.
Integrity
LowLimited modification of data is possible.
Availability
LowPerformance or availability is reduced.

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L. Scored by CNA (github.com).

Official 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, to_absolute_normalized_path in internal/gatewayapi/luavalidator/security.lua does not collapse redundant separators before is_critical_path evaluates Lua submitted through EnvoyExtensionPolicy during default Strict validation. Linux resolves a double-slash absolute path as the corresponding single-slash path, but the validator does not match the redundant-separator form, allowing submitted Lua to read arbitrary files from the gateway controller pod. Exposed files can include Kubernetes service-account tokens, TLS certificates, and process environment data, and the disclosed credentials can provide access to sensitive Kubernetes API Server or Gateway xDS server information. This issue is fixed in versions 1.7.4 and 1.8.1.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Input Validation

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

How developers prevent this class of flaw

  • Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build recognizers for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of allowing parser code to be scattered throughout the program, where it could be subject to errors or inconsistencies that create weaknesses.
  • Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
  • Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.

More Improper Input Validation vulnerabilities (CWE-20)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in gateway

All gateway vulnerabilities

Recent Improper Input Validation vulnerabilities

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