CVE-2026-108865

Description

AmoyLab Unla through 0.10.0 contains an authentication bypass vulnerability that allows unauthenticated attackers to obtain valid access tokens because the OAuth2 server never authenticates a resource owner. Attackers can register a client, request a code from /authorize, and exchange it at /token to access OAuth2-protected MCP prefixes, proxied upstream APIs and injected credentials.

References

• https://github.com/AmoyLab/Unla
• https://github.com/AmoyLab/Unla/blob/v0.10.0/internal/auth/oauth.go#L86-L147
• https://github.com/AmoyLab/Unla/blob/v0.10.0/internal/core/server.go#L229-L261
• https://hackmd.io/@1ExmmukzRMWN7B4gQ4W-4Q/amoylab-unla-oauth-self-issued-token-authz
• https://www.vulncheck.com/advisories/amoylab-unla-through-0.10.0-oauth2-authentication-bypass-via-authorize