Vulnerability · Published Aug 27, 2026 · Assigned by VulnCheck

CVE-2026-81664OpenFaaS Gateway 0.27.11 through 0.27.13 Missing Authentication on the /system/telemetry Route

Medium 5.3

In plain English

A medium-severity missing authentication in faas from openfaas. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 31% of all known vulnerabilities).

Severity (CVSS 3.1)5.3Medium

Exploit odds (30 days)0.4%top 69.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
openfaas	faas	0.27.11 – before 0.27.14

Weakness: CWE-306 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

References

geo-chen/oss: OpenFaaS telemetry finding third-party-advisory
https://github.com/openfaas/faas product
Protect telemetry with BasicAuth patch
https://github.com/openfaas/faas/blob/0.27.13/gateway/main.go#L216 technical-description
VulnCheck Advisory: OpenFaaS Gateway 0.27.11 through 0.27.13 Missing Authentication on the /system/telemetry Route third-party-advisory