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.
CVE-2026-81664
MEDIUMPre-NVD 5.35.3—Trending — 4 sources updated this week
EchelonGraph scoreHIGH confidence
Score 5.3 from GitHub Security Advisory published 2026-08-27. a secondary CVSS source baseline 5.3; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.3Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 5.3
- EG Score
- 5.3(high)
- EG Risk
- 28(Track)EG Risk 28/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity53% × 45%Exploitation0% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 21%
- KEV
- Not listed
Published
August 27, 2026
Last Modified
August 27, 2026
Advisory Details (5)
Auto-updated Aug 27, 2026🔬 Proof of concept available. Patch available. Sources: github_commit.
generic
OpenFaaS Gateway 0.27.11 through 0.27.13 Missing Authentication on the /system/telemetry Route | Advisories | VulnCheck
https://www.vulncheck.com/advisories/openfaas-gateway-0.27.11-through-0.27.13-missing-authentication-on-the-system-telemetry-routegeneric
faas/gateway/main.go at 0.27.13 · openfaas/faas · GitHub
https://github.com/openfaas/faas/blob/0.27.13/gateway/main.go#L216github_commit Patch Available
commit 8d803bf9e265 (openfaas/faas)
Patch available: openfaas/faas 0.27.14 (contains commit 8d803bf9e265)
https://github.com/openfaas/faas/commit/8d803bf9e2655aec6a60fd0e25b392839f96af95generic🟡 PoC Available
GitHub - openfaas/faas: OpenFaaS - Serverless Functions Made Simple · GitHub
https://github.com/openfaas/faasVendor Advisories for CVE-2026-81664(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 9× in last 7d / 9× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-08-30 01:22 UTCEPSS rescore
- 2026-08-29 21:09 UTCEG score recompute
- 2026-08-29 21:08 UTCGHSA enrichment
- 2026-08-28 21:42 UTCEPSS rescore
- 2026-08-28 19:22 UTCEG score recompute
- 2026-08-28 19:22 UTCGHSA enrichment
- 2026-08-27 17:25 UTCEG score recompute
- 2026-08-27 16:47 UTCEG score recompute
- 2026-08-27 16:43 UTCMITRE cvelistV5first tracked
Frequently asked(5)
What is CVE-2026-81664?
CVE-2026-81664 is a medium vulnerability published on August 27, 2026. The OpenFaaS gateway registers GET /system/telemetry in gateway/main.go and, when basicauth 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…
When was CVE-2026-81664 disclosed?
CVE-2026-81664 was first published in the National Vulnerability Database on August 27, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-81664 actively exploited?
CVE-2026-81664 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 78.8% of all scored CVEs.
What is the CVSS score of CVE-2026-81664?
CVE-2026-81664 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-81664?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-81664, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-81664
Is Your Infrastructure Affected by CVE-2026-81664?
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