In Eclipse Lyo versions 2.0.0 to 7.0.0, OAuth server authorization checks can be bypassed when the 2-legged auth is supported by the server. In those cases, application that based their authz filters upon Lyo-provided `AbstractAdapterCredentialsFilter`, are vulnerable. An attacked can create a provisional trusted client (valid use-case) but then it can be used as a trusted client immediately without requiring the administrator approval to clear the provisional status. The 3-legged path requiring user interaction is not vulnerable and rejects provisional clients.
History

Fri, 28 Aug 2026 15:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Fri, 28 Aug 2026 15:00:00 +0000

Type Values Removed Values Added
First Time appeared Eclipse
Eclipse lyo
Vendors & Products Eclipse
Eclipse lyo

Fri, 28 Aug 2026 11:30:00 +0000

Type Values Removed Values Added
Description In Eclipse Lyo versions 2.0.0 to 7.0.0, OAuth server authorization checks can be bypassed when the 2-legged auth is supported by the server. In those cases, application that based their authz filters upon Lyo-provided `AbstractAdapterCredentialsFilter`, are vulnerable. An attacked can create a provisional trusted client (valid use-case) but then it can be used as a trusted client immediately without requiring the administrator approval to clear the provisional status. The 3-legged path requiring user interaction is not vulnerable and rejects provisional clients.
Title OAuth 1.0 session-fixation chain via unauthenticated provisional-consumer registration and insecure v1_0Allowed default
Weaknesses CWE-863
References
Metrics cvssV4_0

{'score': 9.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/AU:Y/R:U/V:C/RE:L/U:Red'}


cve-icon MITRE

Status: PUBLISHED

Assigner: eclipse

Published: 2026-08-28T08:54:07.990Z

Updated: 2026-08-31T12:27:40.249Z

Reserved: 2026-08-05T07:44:04.388Z

Link: CVE-2026-18918

cve-icon Vulnrichment

Updated: 2026-08-28T15:04:10.782Z

cve-icon NVD

Status : Deferred

Published: 2026-08-28T12:16:27.150

Modified: 2026-09-01T21:11:35.983

Link: CVE-2026-18918

cve-icon Redhat

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