{"cve":"CVE-2026-118669","nvd":{"published":"2026-10-28T22:17:12.610","modified":"2026-10-28T22:17:12.610","status":"Received","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.","cvss_v4":{"vector":"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","score":8.4},"cvss_v3":null,"cwes":["CWE-863"],"references":["https://github.com/oauthlib/oauthlib/commit/c951a1d09f99f14e3240973fa83c4f4287d4753d","https://github.com/oauthlib/oauthlib/pull/920","https://github.com/oauthlib/oauthlib/releases/tag/v4.0.0","https://github.com/oauthlib/oauthlib/security/advisories/GHSA-7984-qgvg-3j9c"],"products":[],"source":"nvd","synced_at":"2026-10-28T22:33:43.436067948+00:00"},"epss":null,"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}