{"id":"UBUNTU-CVE-2026-118669","details":"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.","modified":"2026-10-31T03:30:07.354890125Z","published":"2026-10-30T00:00:00Z","upstream":["CVE-2026-118669"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-118669"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-118669"},{"type":"REPORT","url":"https://github.com/oauthlib/oauthlib/commit/c951a1d09f99f14e3240973fa83c4f4287d4753d"},{"type":"REPORT","url":"https://github.com/oauthlib/oauthlib/pull/920"},{"type":"REPORT","url":"https://github.com/oauthlib/oauthlib/releases/tag/v4.0.0"},{"type":"REPORT","url":"https://github.com/oauthlib/oauthlib/security/advisories/GHSA-7984-qgvg-3j9c"}],"affected":[{"package":{"name":"python-oauthlib","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/python-oauthlib?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0.0-1","1.0.3-1"],"ecosystem_specific":{"binaries":[{"binary_name":"python-oauthlib","binary_version":"1.0.3-1"},{"binary_version":"1.0.3-1","binary_name":"python3-oauthlib"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-118669.json"}},{"package":{"name":"python-oauthlib","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/python-oauthlib?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.0.1-1","2.0.4-1","2.0.6-1"],"ecosystem_specific":{"binaries":[{"binary_name":"python-oauthlib","binary_version":"2.0.6-1"},{"binary_version":"2.0.6-1","binary_name":"python3-oauthlib"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-118669.json"}},{"package":{"name":"python-oauthlib","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/python-oauthlib?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.1.0-1","3.1.0-1ubuntu1","3.1.0-1ubuntu2"],"ecosystem_specific":{"binaries":[{"binary_name":"python3-oauthlib","binary_version":"3.1.0-1ubuntu2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-118669.json"}},{"package":{"name":"python-oauthlib","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/python-oauthlib?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.1.0-2","3.1.1-1","3.2.0-1","3.2.0-1ubuntu0.1"],"ecosystem_specific":{"binaries":[{"binary_version":"3.2.0-1ubuntu0.1","binary_name":"python3-oauthlib"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-118669.json"}},{"package":{"name":"python-oauthlib","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/python-oauthlib?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.2.2-1"],"ecosystem_specific":{"binaries":[{"binary_version":"3.2.2-1","binary_name":"python3-oauthlib"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-118669.json"}},{"package":{"name":"python-oauthlib","ecosystem":"Ubuntu:26.10","purl":"pkg:deb/ubuntu/python-oauthlib?arch=source&distro=stonking"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.3.1-1build1","3.3.1-2"],"ecosystem_specific":{"binaries":[{"binary_name":"python3-oauthlib","binary_version":"3.3.1-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-118669.json"}},{"package":{"name":"python-oauthlib","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/python-oauthlib?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.2.2-3","3.3.1-1","3.3.1-1build1"],"ecosystem_specific":{"binaries":[{"binary_version":"3.3.1-1build1","binary_name":"python3-oauthlib"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-118669.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V4","score":"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"},{"type":"Ubuntu","score":"medium"}]}