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.

CVSS 4.0

8.8CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N

CVSS 3.1

8.2CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

EPSS

0.3% chance of exploitation in the next 30 days; higher than 25% of CVEs (scores of 2026-10-25)

CWE

CWE-287

Published

2026-10-11

Modified

2026-10-16

Record from

the NVD, synced 2026-10-19

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

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