CVE-2026-49272
OAuthLib: Bearer token can be retrieved as long as client knows a valid client ID for device workflow
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
Description
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High8.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:N |
| NVDNVD · Received | 3.1 | High8.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:N |
- EPSS (exploitation in 30 days)
- 0.33% · top 74% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.5.
Weakness
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- PyPIoauthlibGHSA-3jp2-3mrg-2vxc (opens in a new tab)
References (4)
- https://github.com/oauthlib/oauthlib/security/advisories/GHSA-3jp2-3mrg-2vxc (opens in a new tab)x_refsource_CONFIRMexploit
- https://github.com/oauthlib/oauthlib/pull/954 (opens in a new tab)x_refsource_MISC
- https://github.com/oauthlib/oauthlib/commit/77a5f1c8ce00da2b0b8c5f6e9cc129920085f114 (opens in a new tab)x_refsource_MISC
- https://github.com/oauthlib/oauthlib/releases/tag/v4.0.1 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-3jp2-3mrg-2vxc (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-49272)Record last updated .