Vulnerability-Lookup

FKIE_CVE-2026-81664

Vulnerability from fkie_nvd - Published: 2026-08-27 17:20 - Updated: 2026-08-27 17:20

Severity

5.3 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

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 0.27.11, 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.

References

	URL	Tags
	disclosure@vulncheck.com	https://github.com/geo-chen/oss/blob/main/faas.md
	disclosure@vulncheck.com	https://github.com/openfaas/faas
	disclosure@vulncheck.com	https://github.com/openfaas/faas/blob/0.27.13/gateway/main.go#L216
	disclosure@vulncheck.com	https://github.com/openfaas/faas/commit/8d803bf9e2655aec6a60fd0e25b392839f96af95
	disclosure@vulncheck.com	https://www.vulncheck.com/advisories/openfaas-gateway-0.27.11-through-0.27.13-missing-authentication-on-the-system-telemetry-route

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "faas",
          "vendor": "openfaas",
          "versions": [
            {
              "lessThan": "0.27.14",
              "status": "affected",
              "version": "0.27.11",
              "versionType": "semver"
            }
          ]
        }
      ],
      "source": "disclosure@vulncheck.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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\u0027s 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."
    }
  ],
  "id": "CVE-2026-81664",
  "lastModified": "2026-08-27T17:20:55.970",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 5.3,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 1.4,
        "source": "disclosure@vulncheck.com",
        "type": "Primary"
      }
    ],
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 6.9,
          "baseSeverity": "MEDIUM",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "NONE",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "userInteraction": "NONE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "version": "4.0",
          "vulnAvailabilityImpact": "NONE",
          "vulnConfidentialityImpact": "LOW",
          "vulnIntegrityImpact": "NONE",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "disclosure@vulncheck.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-08-27T17:20:55.970",
  "references": [
    {
      "source": "disclosure@vulncheck.com",
      "url": "https://github.com/geo-chen/oss/blob/main/faas.md"
    },
    {
      "source": "disclosure@vulncheck.com",
      "url": "https://github.com/openfaas/faas"
    },
    {
      "source": "disclosure@vulncheck.com",
      "url": "https://github.com/openfaas/faas/blob/0.27.13/gateway/main.go#L216"
    },
    {
      "source": "disclosure@vulncheck.com",
      "url": "https://github.com/openfaas/faas/commit/8d803bf9e2655aec6a60fd0e25b392839f96af95"
    },
    {
      "source": "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"
    }
  ],
  "sourceIdentifier": "disclosure@vulncheck.com",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-306"
        }
      ],
      "source": "disclosure@vulncheck.com",
      "type": "Primary"
    }
  ]
}

CVE-2026-81664 (GCVE-0-2026-81664)

Vulnerability from cvelistv5 – Published: 2026-08-27 14:50 – Updated: 2026-08-27 14:50

Title

OpenFaaS Gateway 0.27.11 through 0.27.13 Missing Authentication on the /system/telemetry Route

Summary

Severity

6.9 (Medium)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

5.3 (Medium)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

CWE

CWE-306 - Missing Authentication for Critical Function

Assigner

VulnCheck mitre root

References

5 references

URL	Tags
https://github.com/geo-chen/oss/blob/main/faas.md	third-party-advisory
https://github.com/openfaas/faas	product
https://github.com/openfaas/faas/commit/8d803bf9e…	patch
https://github.com/openfaas/faas/blob/0.27.13/gat…	technical-description
https://www.vulncheck.com/advisories/openfaas-gat…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
openfaas	faas	Affected: 0.27.11 , < 0.27.14 (semver)

Date Public

2026-08-26 00:00

Credits

George Chen

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "faas",
          "vendor": "openfaas",
          "versions": [
            {
              "lessThan": "0.27.14",
              "status": "affected",
              "version": "0.27.11",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "reporter",
          "value": "George Chen"
        }
      ],
      "datePublic": "2026-08-26T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "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\u0027s 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."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 6.9,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "LOW",
            "vulnIntegrityImpact": "NONE"
          },
          "format": "CVSS"
        },
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 5.3,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
            "version": "3.1"
          },
          "format": "CVSS"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-306",
              "description": "Missing Authentication for Critical Function",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-27T14:50:43.397Z",
        "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "shortName": "VulnCheck"
      },
      "references": [
        {
          "name": "geo-chen/oss: OpenFaaS telemetry finding",
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://github.com/geo-chen/oss/blob/main/faas.md"
        },
        {
          "tags": [
            "product"
          ],
          "url": "https://github.com/openfaas/faas"
        },
        {
          "name": "Protect telemetry with BasicAuth",
          "tags": [
            "patch"
          ],
          "url": "https://github.com/openfaas/faas/commit/8d803bf9e2655aec6a60fd0e25b392839f96af95"
        },
        {
          "tags": [
            "technical-description"
          ],
          "url": "https://github.com/openfaas/faas/blob/0.27.13/gateway/main.go#L216"
        },
        {
          "name": "VulnCheck Advisory: OpenFaaS Gateway 0.27.11 through 0.27.13 Missing Authentication on the /system/telemetry Route",
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://www.vulncheck.com/advisories/openfaas-gateway-0.27.11-through-0.27.13-missing-authentication-on-the-system-telemetry-route"
        }
      ],
      "title": "OpenFaaS Gateway 0.27.11 through 0.27.13 Missing Authentication on the /system/telemetry Route",
      "x_generator": {
        "engine": "vulncheck-endgame"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2026-81664",
    "datePublished": "2026-08-27T14:50:43.397Z",
    "dateReserved": "2026-08-27T10:36:58.425Z",
    "dateUpdated": "2026-08-27T14:50:43.397Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

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FKIE_CVE-2026-81664

CVE-2026-81664 (GCVE-0-2026-81664)

Tags

Sightings

Nomenclature