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Fencer Intel
high 8.5

CVE-2026-49272 json

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

published 19d ago modified 6d ago also EUVD-2026-117800 , GHSA-3jp2-3mrg-2vxc

cvss
8.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 26%
public exploits
0
none known

Summary

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.

Patch / fix

  • pypi oauthlib 4.0.1
  • oauthlib_project oauthlib 4.0.1
  • python-oauthlib openSUSE Tumbleweed 4.0.1-1.1

opensuse advisories openSUSE-SU-2026:12520-1

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-49272 updated cvss 8.5

oauthlib: oauthlib: Authentication bypass via missing device code validation

  • Red Hat OpenShift AI (RHOAI) rhoai/odh-mlflow-rhel9
    not affected: vulnerable code not in execute path

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
6d ago

Exploit prediction

0.33% chance of exploitation in the next 30 days, higher than 26% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/oauthlib/oauthlib/security/advisories/GHSA-3jp2-3mrg-2vxc referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 8.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:N
GitHub 3.1 8.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:N

Affected packages

ecosystem package affected fixed in
pypi oauthlib
>=3.3.0, <4.0.1
4.0.1

Affected products

  • oauthlib oauthlib

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of oauthlib/oauthlib published their own advisory on GitHub. Reviewed sources take precedence over it.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.