CVE-2026-108716

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.

CVSS 4.0

6.0CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

CVSS 3.1

5.3CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N

EPSS

0.2% chance of exploitation in the next 30 days; higher than 9% of CVEs (scores of 2026-10-25)

CWE

CWE-319

Published

2026-10-11

Modified

2026-10-16

Record from

the NVD, synced 2026-10-19

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

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