Auth bypass in Amoylab Unla
CVE-2026-108865
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.
Vulnerability class: Broken Authentication
Published .
CVSS v3 metric
CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- hackmd.io/@1ExmmukzRMWN7B4gQ4W-4Q/amoylab-unla-oauth-self-issued-token-authz (third-party-advisory)
- github.com/AmoyLab/Unla/blob/v0.10.0/internal/auth/oauth.go (technical-description)
- github.com/AmoyLab/Unla/blob/v0.10.0/internal/core/server.go (technical-description)
- github.com/AmoyLab/Unla (product)
- www.vulncheck.com/advisories/amoylab-unla-through-0.10.0-oauth2-authentication-… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-108865?
- CVE-2026-108865 is a high-severity vulnerability in Amoylab Unla, classified under Improper Authentication. CVSS score: 8.2/10. Published 2026-10-11.
- How severe is CVE-2026-108865?
- High severity. CVSS v3 base score is 8.2 out of 10.