8.5 High

OAuthLib: Bearer token can be retrieved as long as client knows a valid client ID for device workflow

CVE-2026-49272

Summary A call to the token endpoint with a grant type of "urn:ietf:params:oauth:grant-type:devicecode" and a bogus devicecode is able to get a bearer token as long as they know a valid client ID enabled for the device workflow. Details [Section 3.4 of the RFC 8628 spec](https://datatracker.ietf.org/doc/html/rfc8628#section-3.4) says that the token endpoint should take in devicecode as a required parameter.DeviceCodeGrant.validatetokenrequest does not perform any validation of devicecode. DeviceCodeGrant.validatetokenrequest should be validating that devicecode was passed in as a parameter and that it is valid, similar to how AuthorizationCodeGrant.validatetokenrequest does the checks [here](https://github.com/oauthlib/oauthlib/blob/a015b446622f2b925517501fe484c10eff7a83c0/oauthlib/oauth2/rfc6749/granttypes/authorizationcode.py#L446) and [here](https://github.com/oauthlib/oauthlib/blob/a015b446622f2b925517501fe484c10eff7a83c0/oauthlib/oauth2/rfc6749/granttypes/authorizationcode.py#L483). I would like to propose a new method be added to RequestValidator called validatedevicecode that is similar to the validatecode method and is called inside of DeviceCodeGrant.validatetokenrequest.…

Assessment

CVSS: 8.5 (v3.1)
Severity: High
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 27 October 2026
Last updated: 27 October 2026
Affected: pip · oauthlib
Weakness: CWE-287

CVSS vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:N

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