CVE-2026-81664

MEDIUMPre-NVD 5.35.3—
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
Trending — 3 sources updated this weekElevated
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: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
5.3
EG Score
5.3(high)
EG Risk
55(Attend)
EG Risk 55/100SSVC: Attend

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 computed
Severity53% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
0%
EPSS %ILE
22%
KEV
Not listed

Published

August 27, 2026

Last Modified

August 31, 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-route
generic

faas/gateway/main.go at 0.27.13 · openfaas/faas · GitHub

https://github.com/openfaas/faas/blob/0.27.13/gateway/main.go#L216
github_commit Patch Available

commit 8d803bf9e265 (openfaas/faas)

Patch available: openfaas/faas 0.27.14 (contains commit 8d803bf9e265)

https://github.com/openfaas/faas/commit/8d803bf9e2655aec6a60fd0e25b392839f96af95
generic🟡 PoC Available

GitHub - openfaas/faas: OpenFaaS - Serverless Functions Made Simple · GitHub

https://github.com/openfaas/faas
generic

oss/faas.md at main · geo-chen/oss · GitHub

https://github.com/geo-chen/oss/blob/main/faas.md

Vendor 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 20× in last 7d / 69× 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.

  1. 2026-09-21 03:18 UTCEG score recompute
  2. 2026-09-21 03:18 UTCGHSA enrichment
  3. 2026-09-20 20:16 UTCEPSS rescore
  4. 2026-09-20 01:33 UTCEG score recompute
  5. 2026-09-20 01:33 UTCGHSA enrichment
  6. 2026-09-18 23:48 UTCEG score recompute
  7. 2026-09-18 23:48 UTCGHSA enrichment
  8. 2026-09-18 19:28 UTCEPSS rescore
  9. 2026-09-17 22:00 UTCEG score recompute
  10. 2026-09-17 22:00 UTCGHSA enrichment
  11. 2026-09-16 20:14 UTCEG score recompute
  12. 2026-09-16 20:14 UTCGHSA enrichment
  13. 2026-09-16 14:08 UTCEPSS rescore
  14. 2026-09-16 05:15 UTCEPSS rescore
  15. 2026-09-15 18:29 UTCEG score recompute
  16. 2026-09-15 18:29 UTCGHSA enrichment
  17. 2026-09-15 03:12 UTCEPSS rescore
  18. 2026-09-15 03:12 UTCEPSS rescore
  19. 2026-09-14 16:09 UTCEG score recompute
  20. 2026-09-14 16:09 UTCGHSA enrichment
  21. 2026-09-13 14:24 UTCEG score recompute
  22. 2026-09-13 14:24 UTCGHSA enrichment
  23. 2026-09-12 12:39 UTCEG score recompute
  24. 2026-09-12 12:39 UTCGHSA enrichment
  25. 2026-09-11 14:53 UTCEPSS rescore
Show 44 more
  1. 2026-09-11 14:53 UTCEPSS rescore
  2. 2026-09-11 10:53 UTCEG score recompute
  3. 2026-09-11 10:53 UTCGHSA enrichment
  4. 2026-09-10 09:03 UTCGHSA enrichment
  5. 2026-09-09 07:07 UTCEG score recompute
  6. 2026-09-09 07:07 UTCGHSA enrichment
  7. 2026-09-08 22:01 UTCEPSS rescore
  8. 2026-09-08 05:23 UTCEG score recompute
  9. 2026-09-08 05:22 UTCGHSA enrichment
  10. 2026-09-07 03:36 UTCEG score recompute
  11. 2026-09-07 03:36 UTCGHSA enrichment
  12. 2026-09-06 13:48 UTCEPSS rescore
  13. 2026-09-06 01:46 UTCEG score recompute
  14. 2026-09-06 01:46 UTCGHSA enrichment
  15. 2026-09-05 15:31 UTCEPSS rescore
  16. 2026-09-05 00:00 UTCEG score recompute
  17. 2026-09-05 00:00 UTCGHSA enrichment
  18. 2026-09-04 05:07 UTCEPSS rescore
  19. 2026-09-03 22:15 UTCGHSA enrichment
  20. 2026-09-02 20:30 UTCEG score recompute
  21. 2026-09-02 20:30 UTCGHSA enrichment
  22. 2026-09-02 14:12 UTCEPSS rescore
  23. 2026-09-01 18:22 UTCEG score recompute
  24. 2026-09-01 18:22 UTCGHSA enrichment
  25. 2026-09-01 13:54 UTCEPSS rescore
  26. 2026-09-01 04:40 UTCEPSS rescore
  27. 2026-09-01 04:40 UTCEPSS rescore
  28. 2026-08-31 16:35 UTCEG score recompute
  29. 2026-08-31 16:35 UTCGHSA enrichment
  30. 2026-08-31 16:01 UTCEG score recompute
  31. 2026-08-31 16:01 UTCGHSA enrichment
  32. 2026-08-30 22:53 UTCEG score recompute
  33. 2026-08-30 22:53 UTCGHSA enrichment
  34. 2026-08-30 19:18 UTCEPSS rescore
  35. 2026-08-30 19:17 UTCEPSS rescore
  36. 2026-08-30 01:22 UTCEPSS rescore
  37. 2026-08-29 21:09 UTCEG score recompute
  38. 2026-08-29 21:08 UTCGHSA enrichment
  39. 2026-08-28 21:42 UTCEPSS rescore
  40. 2026-08-28 19:22 UTCEG score recompute
  41. 2026-08-28 19:22 UTCGHSA enrichment
  42. 2026-08-27 17:25 UTCEG score recompute
  43. 2026-08-27 16:47 UTCEG score recompute
  44. 2026-08-27 16:43 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

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, with the most recent update on August 31, 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 78.1% 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

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