CVE-2026-81664

MEDIUMPre-NVD 5.35.3
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

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, GitHub Security Advisory, a secondary CVSS source
Elevated

Also known asEUVD-2026-67033 (ENISA EUVD) · GHSA-gwq3-cphc-pwmg (GitHub Security Advisories)Source: ENISA EUVD

5.3EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 5.3Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

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
5.3MEDIUMmedium confidence
EG Risk
55
EG Risk 55/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity53% × 45%
Impact severity (EG Severity): CVSS 5.3 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.4%
EPSS %ILE
30th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (5.3): severity, escalated by confirmed exploitation. This CVE's 5.3 is its impact severity (EG Severity), not escalated.

EG Severity
5.3 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-24). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; 60 days if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

August 27, 2026

Last Modified

September 24, 2026

Advisory Details (5)

Auto-updated Aug 27, 2026
Patch available. Sources: github_commit.
Web page

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
Web page

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
Web page

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

https://github.com/openfaas/faas
Web page

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 8× in last 7d / 52× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 99 of 148 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 1 repeat row among the latest 100 is merged into the row it repeats. The 49 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  2. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  3. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  4. 2026-10-30 01:55 UTCOSV refresh
  5. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  6. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  7. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  8. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  9. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  10. 2026-10-25 13:58 UTCEG score recompute
  11. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  12. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  13. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  14. 2026-10-22 13:48 UTCEG score recompute
  15. 2026-10-22 13:47 UTCGHSA enrichmentGHSA-gwq3-cphc-pwmg · GitHub CVSS 5.3
  16. 2026-10-21 16:34 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  17. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  18. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  19. 2026-10-18 16:33 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  20. 2026-10-18 03:09 UTCEG score recompute
  21. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  22. 2026-10-16 16:44 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  23. 2026-10-15 16:33 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  24. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  25. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.4% · 28th percentile
Show 74 more
  1. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  2. 2026-10-12 14:56 UTCEG score recompute
  3. 2026-10-11 19:20 UTCEG score recompute
  4. 2026-10-11 16:37 UTCEG score recompute
  5. 2026-10-11 13:54 UTCEG score recompute
  6. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  7. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  8. 2026-10-10 09:47 UTCEG score recompute
  9. 2026-10-10 09:47 UTCGHSA enrichmentGHSA-gwq3-cphc-pwmg · GitHub CVSS 5.3
  10. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  11. 2026-10-09 06:18 UTCEG score recompute
  12. 2026-10-09 06:18 UTCGHSA enrichmentGHSA-gwq3-cphc-pwmg · GitHub CVSS 5.3
  13. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  14. 2026-10-08 04:33 UTCEG score recompute
  15. 2026-10-08 04:33 UTCGHSA enrichmentGHSA-gwq3-cphc-pwmg · GitHub CVSS 5.3
  16. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  17. 2026-10-07 02:39 UTCEG score recompute
  18. 2026-10-07 02:39 UTCGHSA enrichmentGHSA-gwq3-cphc-pwmg · GitHub CVSS 5.3
  19. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  20. 2026-10-06 00:54 UTCEG score recompute
  21. 2026-10-06 00:54 UTCGHSA enrichmentGHSA-gwq3-cphc-pwmg · GitHub CVSS 5.3
  22. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  23. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  24. 2026-10-04 19:39 UTCGHSA enrichmentGHSA-gwq3-cphc-pwmg · GitHub CVSS 5.3
  25. 2026-10-03 15:13 UTCEG score recompute
  26. 2026-10-03 15:13 UTCGHSA enrichmentGHSA-gwq3-cphc-pwmg · GitHub CVSS 5.3
  27. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  28. 2026-10-02 17:57 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  29. 2026-10-02 08:38 UTCEG score recompute
  30. 2026-10-02 08:38 UTCGHSA enrichmentGHSA-gwq3-cphc-pwmg · GitHub CVSS 5.3
  31. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  32. 2026-10-01 06:53 UTCEG score recompute
  33. 2026-10-01 06:53 UTCGHSA enrichmentGHSA-gwq3-cphc-pwmg · GitHub CVSS 5.3
  34. 2026-09-30 15:04 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  35. 2026-09-30 05:02 UTCEG score recompute
  36. 2026-09-30 05:02 UTCGHSA enrichmentGHSA-gwq3-cphc-pwmg · GitHub CVSS 5.3
  37. 2026-09-28 22:21 UTCEG score recompute
  38. 2026-09-28 22:21 UTCGHSA enrichmentGHSA-gwq3-cphc-pwmg · GitHub CVSS 5.3
  39. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  40. 2026-09-27 20:30 UTCEG score recompute
  41. 2026-09-27 20:30 UTCGHSA enrichmentGHSA-gwq3-cphc-pwmg · GitHub CVSS 5.3
  42. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  43. 2026-09-26 18:45 UTCEG score recompute
  44. 2026-09-26 18:45 UTCGHSA enrichmentGHSA-gwq3-cphc-pwmg · GitHub CVSS 5.3
  45. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.4% · 27th percentile
  46. 2026-09-24 21:14 UTCEG score recompute
  47. 2026-09-24 21:14 UTCGHSA enrichmentGHSA-gwq3-cphc-pwmg · GitHub CVSS 5.3
  48. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  49. 2026-09-24 08:34 UTCGHSA enrichmentGHSA-gwq3-cphc-pwmg · GitHub CVSS 5.3
  50. 2026-09-23 06:49 UTCEG score recompute
  51. 2026-09-23 06:49 UTCGHSA enrichmentGHSA-gwq3-cphc-pwmg · GitHub CVSS 5.3
  52. 2026-09-22 16:01 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  53. 2026-09-22 05:04 UTCEG score recompute
  54. 2026-09-22 05:03 UTCGHSA enrichmentGHSA-gwq3-cphc-pwmg · GitHub CVSS 5.3
  55. 2026-09-21 21:09 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  56. 2026-09-21 03:18 UTCEG score recompute
  57. 2026-09-21 03:18 UTCGHSA enrichmentGHSA-gwq3-cphc-pwmg · GitHub CVSS 5.3
  58. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  59. 2026-09-20 01:33 UTCEG score recompute
  60. 2026-09-20 01:33 UTCGHSA enrichmentGHSA-gwq3-cphc-pwmg · GitHub CVSS 5.3
  61. 2026-09-18 23:48 UTCEG score recompute
  62. 2026-09-18 23:48 UTCGHSA enrichmentGHSA-gwq3-cphc-pwmg · GitHub CVSS 5.3
  63. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  64. 2026-09-17 22:00 UTCEG score recompute
  65. 2026-09-17 22:00 UTCGHSA enrichmentGHSA-gwq3-cphc-pwmg · GitHub CVSS 5.3
  66. 2026-09-16 20:14 UTCEG score recompute
  67. 2026-09-16 20:14 UTCGHSA enrichmentGHSA-gwq3-cphc-pwmg · GitHub CVSS 5.3
  68. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  69. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  70. 2026-09-15 18:29 UTCEG score recompute
  71. 2026-09-15 18:29 UTCGHSA enrichmentGHSA-gwq3-cphc-pwmg · GitHub CVSS 5.3
  72. 2026-09-15 03:12 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  73. 2026-09-14 16:09 UTCEG score recompute
  74. 2026-09-14 16:09 UTCGHSA enrichmentGHSA-gwq3-cphc-pwmg · GitHub CVSS 5.3

Frequently asked(5)

What is CVE-2026-81664?
CVE-2026-81664 is a medium-severity vulnerability; its CVE record was published on August 27, 2026. 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…
When was CVE-2026-81664 made public?
CVE-2026-81664 was made public on August 26, 2026: that is the date its CVE record's CNA, VulnCheck, gives for when the vulnerability was made public. The CVE record itself was published on August 27, 2026. EchelonGraph's copy of the record carries a last-modified date of September 24, 2026; the record at its source may have been updated since.
Is CVE-2026-81664 actively exploited?
CVE-2026-81664 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (30th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-81664?
CVE-2026-81664 has a CVSS base score of 5.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-81664?
A fix for CVE-2026-81664 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-81664 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-81664

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