CVE-2026-49272
OAuthLib: Bearer token can be retrieved as long as client knows a valid client ID for device workflow
CVSS Score
8.5
EPSS Score
0.0%
EPSS Percentile
0th
OAuthLib is an implementation of the OAuth request-signing logic for Python 3.6+. From 3.3.0 until 4.0.1, OAuthLib's RFC 8628 device workflow does not require DeviceCodeGrant.validate_token_request to check that the device_code parameter is present and valid. A caller whose client request is accepted by the configured validator and who knows a valid client ID enabled for the device workflow can submit a missing or bogus device code to the token endpoint and obtain a bearer token without completing device authorization. This issue is fixed in version 4.0.1.
| CWE | CWE-287 |
| Vendor | oauthlib |
| Product | oauthlib |
| Published | Nov 5, 2026 |
| Last Updated | Nov 5, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Changed
Confidentiality
Low
Integrity
High
Availability
None
Affected Versions
oauthlib / oauthlib
>= 3.3.0, < 4.0.1
References
github.com: https://github.com/oauthlib/oauthlib/security/advisories/GHSA-3jp2-3mrg-2vxc github.com: https://github.com/oauthlib/oauthlib/pull/954 github.com: https://github.com/oauthlib/oauthlib/commit/77a5f1c8ce00da2b0b8c5f6e9cc129920085f114 github.com: https://github.com/oauthlib/oauthlib/releases/tag/v4.0.1