CVE-2026-108716

EUVD-2026-96990
mcp-remote 0.8.0 through 0.14.3 contains a cleartext transmission vulnerability in authorizeWithDeviceCode that sends client secrets and receives tokens without enforcing HTTPS endpoints. When discovered device authorization and token endpoints are non-loopback http URLs, on-path network attackers can capture the client secret plus issued access and refresh tokens.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
5.3 MEDIUM
NETWORK
HIGH
NONE
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N
Awaiting analysis
This vulnerability is currently awaiting analysis.
Base Score
CVSS 3.x
EPSS Score
Percentile: 9.04%
Common Weakness Enumeration
References
https://github.com/punkpeye/mcp-remote
https://github.com/punkpeye/mcp-remote/blob/v0.14.3/src/lib/client-credentials.ts#L37-L47
https://github.com/punkpeye/mcp-remote/blob/v0.14.3/src/lib/device-authorization.ts#L64-L170
https://hackmd.io/@haind03/punkpeye-mcp-remote-device-code-cleartext-oauth-transport
https://www.vulncheck.com/advisories/mcp-remote-0.8.0-through-0.14.3-cleartext-credential-transmission-via-device-code-oauth-grant