CVE-2026-108716: mcp-remote 0.8.0 through 0.14.3 Cleartext Credential Transmission via --device-code OAuth Grant

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-11 · updated 2026-10-16
Weakness: CWE-319

Description

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.

Affected products

punkpeye mcp-remote: from 0.8.0 through 0.14.3

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

Get alerted when CVE-2026-108716 or the next vulnerability affects your stack