{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "oauthlib",
          "vendor": "oauthlib",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 4.0.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "OAuthLib is an implementation of the OAuth request-signing logic for Python 3.6+. Prior to 4.0.0, the client_credentials and Resource Owner Password Credentials token grant handlers can authenticate request.client as one confidential client while retaining an attacker-supplied request.client_id for validate_grant_type and validate_scopes. A lower-privilege authenticated client can therefore cause grant and scope authorization to use another client\u0027s identity when an application validator relies on the documented client_id argument, potentially issuing tokens with unauthorized grants or scopes. Validators that authorize exclusively from request.client may not be affected. This issue is fixed in version 4.0.0."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 8.4,
            "baseSeverity": "HIGH",
            "privilegesRequired": "LOW",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "HIGH",
            "subIntegrityImpact": "HIGH",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:H/SI:H/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "HIGH"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-863",
              "description": "CWE-863: Incorrect Authorization",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-28T21:09:58.893Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/oauthlib/oauthlib/security/advisories/GHSA-7984-qgvg-3j9c",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/oauthlib/oauthlib/security/advisories/GHSA-7984-qgvg-3j9c"
        },
        {
          "name": "https://github.com/oauthlib/oauthlib/pull/920",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/oauthlib/oauthlib/pull/920"
        },
        {
          "name": "https://github.com/oauthlib/oauthlib/commit/c951a1d09f99f14e3240973fa83c4f4287d4753d",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/oauthlib/oauthlib/commit/c951a1d09f99f14e3240973fa83c4f4287d4753d"
        },
        {
          "name": "https://github.com/oauthlib/oauthlib/releases/tag/v4.0.0",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/oauthlib/oauthlib/releases/tag/v4.0.0"
        }
      ],
      "source": {
        "advisory": "GHSA-7984-qgvg-3j9c",
        "discovery": "UNKNOWN"
      },
      "title": "OAuthLib: Token grants can use attacker-supplied client_id for authorization after authenticating a different client"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-118669",
    "datePublished": "2026-10-28T21:09:58.893Z",
    "dateReserved": "2026-10-28T17:25:37.562Z",
    "dateUpdated": "2026-10-28T21:09:58.893Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}