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Fencer Vulns
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 2026-10-27 12 d ago modified 2026-11-05 3 d ago also GHSA-3jp2-3mrg-2vxc , EUVD-2026-117800

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

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
3 d ago

Exploit prediction

0.33% chance of exploitation in the next 30 days, higher than 26% of all scored CVEs (FIRST EPSS, 2026-11-08).

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 Vulns 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.