---
id: CVE-2026-81664
title: >-
  The OpenFaaS gateway registers GET /system/telemetry in gateway/main.go and,
  when basic_auth is enabled, wraps each administrative /system/* handler in
  auth.DecorateWithBasicAuth
summary: >-
  The OpenFaaS gateway registers GET /system/telemetry in gateway/main.go and,
  when basic_auth is enabled, wraps each administrative /system/* handler in
  auth.DecorateWithBasicAuth. TelemetryHandler was left out of that wrap block
  from 0.2…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N'
cwe:
  - CWE-306
published: '2026-08-27'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T20:43:32.537'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-81664'
references:
  - url: 'https://github.com/geo-chen/oss/blob/main/faas.md'
    label: disclosure@vulncheck.com
  - url: 'https://github.com/openfaas/faas'
    label: disclosure@vulncheck.com
  - url: 'https://github.com/openfaas/faas/blob/0.27.13/gateway/main.go#L216'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/openfaas/faas/commit/8d803bf9e2655aec6a60fd0e25b392839f96af95
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/openfaas-gateway-0.27.11-through-0.27.13-missing-authentication-on-the-system-telemetry-route
    label: disclosure@vulncheck.com
  - url: 'https://github.com/geo-chen/oss/blob/main/faas.md'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
epss: 0.00397
epssPercentile: 0.3109
ingestedAt: '2026-09-24T20:51:40.236Z'
---

## Overview

The OpenFaaS gateway registers GET /system/telemetry in gateway/main.go and, when basic_auth is enabled, wraps each administrative /system/* handler in auth.DecorateWithBasicAuth. TelemetryHandler was left out of that wrap block from 0.27.11, which introduced the route, until 0.27.14, which added it. On an affected gateway the route therefore reaches the forwarding proxy with no credential check and returns whatever the configured provider serves for /system/telemetry, so any client that can reach the gateway port can read the provider's telemetry regardless of the basic_auth setting. The exposed content depends on the provider, and covers resource and invocation metrics for faasd and pod or cluster state for faas-netes.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.