Vulnerability-Lookup

CVE-2026-61709 (GCVE-0-2026-61709)

Vulnerability from cvelistv5 – Published: 2026-09-16 14:05 – Updated: 2026-09-16 14:05

Title

OpenFGA: ListUsers returns a deliberately-excluded user (authorization-decision over-inclusion) when a `but not` exclusion under a type-bound wildcard is intersected (`and`) with another relation that also grants that user

Summary

OpenFGA is an authorization and permission engine built for developers. Prior to 1.18.1, the ListUsers API could return a user that should have been excluded when an authorization relation used an intersection containing a base but not excluded operand, the base was granted through a type-bound public wildcard, and the excluded user also had a concrete tuple through another intersection operand. In pkg/server/commands/listusers/list_users_rpc.go, expandIntersection counted the concrete tuple and wildcard without first rejecting entries in excludedUsersMap. Applications that used ListUsers to enumerate or enforce access could therefore treat an excluded user as authorized. This issue is fixed in version 1.18.1.

Severity

5.3 (Medium)


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

CWE

CWE-281 - Improper Preservation of Permissions
CWE-863 - Incorrect Authorization

Assigner

GitHub_M mitre root

References

3 references

URL	Tags
https://github.com/openfga/openfga/security/advis…	x_refsource_CONFIRM
https://github.com/openfga/openfga/commit/171806c…	x_refsource_MISC
https://github.com/openfga/openfga/releases/tag/v1.18.1	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version	CPE status
openfga	openfga	Affected: < 1.18.1	guessed

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "openfga",
          "vendor": "openfga",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.18.1"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "OpenFGA is an authorization and permission engine built for developers. Prior to 1.18.1, the ListUsers API could return a user that should have been excluded when an authorization relation used an intersection containing a base but not excluded operand, the base was granted through a type-bound public wildcard, and the excluded user also had a concrete tuple through another intersection operand. In pkg/server/commands/listusers/list_users_rpc.go, expandIntersection counted the concrete tuple and wildcard without first rejecting entries in excludedUsersMap. Applications that used ListUsers to enumerate or enforce access could therefore treat an excluded user as authorized. This issue is fixed in version 1.18.1."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 5.3,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "NONE",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-281",
              "description": "CWE-281: Improper Preservation of Permissions",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-863",
              "description": "CWE-863: Incorrect Authorization",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-16T14:05:35.455Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/openfga/openfga/security/advisories/GHSA-g3pg-frfm-pr2m",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/openfga/openfga/security/advisories/GHSA-g3pg-frfm-pr2m"
        },
        {
          "name": "https://github.com/openfga/openfga/commit/171806c93b86bca29e0212ceb8b6ee9c48eb9ac3",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/openfga/openfga/commit/171806c93b86bca29e0212ceb8b6ee9c48eb9ac3"
        },
        {
          "name": "https://github.com/openfga/openfga/releases/tag/v1.18.1",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/openfga/openfga/releases/tag/v1.18.1"
        }
      ],
      "source": {
        "advisory": "GHSA-g3pg-frfm-pr2m",
        "discovery": "UNKNOWN"
      },
      "title": "OpenFGA: ListUsers returns a deliberately-excluded user (authorization-decision over-inclusion) when a `but not` exclusion under a type-bound wildcard is intersected (`and`) with another relation that also grants that user"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-61709",
    "datePublished": "2026-09-16T14:05:35.455Z",
    "dateReserved": "2026-07-10T18:51:13.919Z",
    "dateUpdated": "2026-09-16T14:05:35.455Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-61709\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-09-16T15:17:39.660\",\"lastModified\":\"2026-09-16T15:17:39.660\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"OpenFGA is an authorization and permission engine built for developers. Prior to 1.18.1, the ListUsers API could return a user that should have been excluded when an authorization relation used an intersection containing a base but not excluded operand, the base was granted through a type-bound public wildcard, and the excluded user also had a concrete tuple through another intersection operand. In pkg/server/commands/listusers/list_users_rpc.go, expandIntersection counted the concrete tuple and wildcard without first rejecting entries in excludedUsersMap. Applications that used ListUsers to enumerate or enforce access could therefore treat an excluded user as authorized. This issue is fixed in version 1.18.1.\"}],\"affected\":[{\"source\":\"security-advisories@github.com\",\"affectedData\":[{\"vendor\":\"openfga\",\"product\":\"openfga\",\"versions\":[{\"version\":\"\u003c 1.18.1\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N\",\"baseScore\":5.3,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"HIGH\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"NONE\"},\"exploitabilityScore\":1.6,\"impactScore\":3.6}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-281\"},{\"lang\":\"en\",\"value\":\"CWE-863\"}]}],\"references\":[{\"url\":\"https://github.com/openfga/openfga/commit/171806c93b86bca29e0212ceb8b6ee9c48eb9ac3\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/openfga/openfga/releases/tag/v1.18.1\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/openfga/openfga/security/advisories/GHSA-g3pg-frfm-pr2m\",\"source\":\"security-advisories@github.com\"}]}}"
  }
}

FKIE_CVE-2026-61709

Vulnerability from fkie_nvd - Published: 2026-09-16 15:17 - Updated: 2026-09-16 15:17

Severity

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

Summary

References

	URL	Tags
	security-advisories@github.com	https://github.com/openfga/openfga/commit/171806c93b86bca29e0212ceb8b6ee9c48eb9ac3
	security-advisories@github.com	https://github.com/openfga/openfga/releases/tag/v1.18.1
	security-advisories@github.com	https://github.com/openfga/openfga/security/advisories/GHSA-g3pg-frfm-pr2m

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "openfga",
          "vendor": "openfga",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.18.1"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "OpenFGA is an authorization and permission engine built for developers. Prior to 1.18.1, the ListUsers API could return a user that should have been excluded when an authorization relation used an intersection containing a base but not excluded operand, the base was granted through a type-bound public wildcard, and the excluded user also had a concrete tuple through another intersection operand. In pkg/server/commands/listusers/list_users_rpc.go, expandIntersection counted the concrete tuple and wildcard without first rejecting entries in excludedUsersMap. Applications that used ListUsers to enumerate or enforce access could therefore treat an excluded user as authorized. This issue is fixed in version 1.18.1."
    }
  ],
  "id": "CVE-2026-61709",
  "lastModified": "2026-09-16T15:17:39.660",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 5.3,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 1.6,
        "impactScore": 3.6,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-09-16T15:17:39.660",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/openfga/openfga/commit/171806c93b86bca29e0212ceb8b6ee9c48eb9ac3"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/openfga/openfga/releases/tag/v1.18.1"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/openfga/openfga/security/advisories/GHSA-g3pg-frfm-pr2m"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-281"
        },
        {
          "lang": "en",
          "value": "CWE-863"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}

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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.