{"id":"CVE-2026-118669","published":"2026-10-28T22:17:12.610","lastModified":"2026-10-28T22:17:12.610","description":"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's 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.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":["CWE-863"],"vendors":[],"products":[],"references":[{"url":"https://github.com/oauthlib/oauthlib/commit/c951a1d09f99f14e3240973fa83c4f4287d4753d","tags":[]},{"url":"https://github.com/oauthlib/oauthlib/pull/920","tags":[]},{"url":"https://github.com/oauthlib/oauthlib/releases/tag/v4.0.0","tags":[]},{"url":"https://github.com/oauthlib/oauthlib/security/advisories/GHSA-7984-qgvg-3j9c","tags":[]}],"exploitRefs":[{"url":"https://github.com/oauthlib/oauthlib/commit/c951a1d09f99f14e3240973fa83c4f4287d4753d","tags":[]},{"url":"https://github.com/oauthlib/oauthlib/pull/920","tags":[]},{"url":"https://github.com/oauthlib/oauthlib/releases/tag/v4.0.0","tags":[]},{"url":"https://github.com/oauthlib/oauthlib/security/advisories/GHSA-7984-qgvg-3j9c","tags":[]}],"hasPoc":true,"ai":null}