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TI-2026-85670 Aliases CVE-2026-49272GHSA-3jp2-3mrg-2vxc

Missing device code check in OAuthLib lets callers get bearer tokens

Priority HIGH 70CWE-287Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
Low · High · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-287.

Summary

OAuthLib from 3.3.0 before 4.0.1 does not require the device_code parameter to be present and valid in DeviceCodeGrant.validate_token_request. An attacker whose client request passes the configured validator and who knows a valid client ID enabled for the device workflow can send a missing or bogus device code to the token endpoint and get a bearer token without completing device authorization. The weakness is classified as CWE-287.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

Description from the CNA

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00328 26th percentileScored 2026-11-07
Fix Fixed oauthlib (oauthlib): 4.0.1oauthlib (PyPI): 4.0.1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
oauthliboauthlib3.3.0 to before 4.0.14.0.1Patch availableCNA
—oauthlib (PyPI)3.3.0 to before 4.0.14.0.1Patch availableGHSA-3jp2-3mrg-2vxc
  • oauthlib Vendoroauthlib Affected 3.3.0 to before 4.0.1 Fixed in 4.0.1 Patch available CNA
  • oauthlib (PyPI) Vendor— Affected 3.3.0 to before 4.0.1 Fixed in 4.0.1 Patch available GHSA-3jp2-3mrg-2vxc

Remediation

Upgrade oauthlib to version 4.0.1, which fixes this issue.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

  • Fix · CNA oauthlib (oauthlib) Fixed in 4.0.1
  • Fix · GHSA-3jp2-3mrg-2vxc oauthlib (PyPI) Fixed in 4.0.1 Advisory →

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat OpenShift AI (RHOAI)

Timeline

  1. 2026-11-05 Threatist record created from CVE-2026-49272
  2. 2026-11-05 CISA SSVC decision points changed
  3. 2026-11-05 Priority changed: MEDIUM → HIGH
  4. 2026-11-05 Alias added: GHSA-3jp2-3mrg-2vxc
  5. 2026-11-05 Fix available: PyPI/[email protected] · GHSA-3jp2-3mrg-2vxc
  6. 2026-11-05 3 new references · GHSA-3jp2-3mrg-2vxc
  7. 2026-11-06 Affected versions changed · Red Hat
  8. 2026-11-06 CVSS score added · Red Hat
  9. 2026-11-06 Affected versions changed · Red Hat

References

Other 5

  • TI-2026-82213 OAuthLib token grants can authorize with another client's identity CVSS 4.0HIGH 8.4
  • TI-2026-71760 Unsafe JSONP callback injection in OAuthLib RevocationEndpoint CVSS 3.1MEDIUM 6.1
  • TI-2026-71761 Timing side channel in OAuthLib PKCE code_verifier comparison CVSS 3.1MEDIUM 6.8

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences