CVE-2026-18918
OAuth 1.0 session-fixation chain via unauthenticated provisional-consumer registration and insecure v1_0Allowed default
- State
- Published
- Severity
- 9.1 Critical
- Published
- Aug 28, 2026
- Updated
- Aug 31, 2026
- Reserved
- Aug 5, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 9.1 Critical | 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 | eclipse |
Weaknesses
Affected Products
| Product | Versions |
|---|---|
Eclipse LyoEclipse Foundation |
|
References
Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.