CVE-2026-107162

high

Description

Express Gateway through 1.16.11 contains an authentication bypass vulnerability in the OAuth 2.0 refresh_token grant that fails to validate the token secret or issuing client. Attackers with any valid client credentials and the identifier portion of another user's refresh token can obtain that user's access token and impersonate them against oauth2-protected APIs.

References

https://www.vulncheck.com/advisories/express-gateway-through-1.16.11-oauth-2.0-refresh-token-validation-bypass

https://github.com/ExpressGateway/express-gateway/issues/1076

https://github.com/ExpressGateway/express-gateway/blob/45612814d12f65889ef3bdf80b2ed7ab9b557736/lib/services/tokens/token.service.js#L100-L136

https://github.com/ExpressGateway/express-gateway/blob/45612814d12f65889ef3bdf80b2ed7ab9b557736/lib/policies/oauth2/oauth2-server.js#L221-L247

https://github.com/ExpressGateway/express-gateway

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-94316

Details

Source: Mitre, NVD

Published: 2026-10-07

Updated: 2026-10-07

Risk Information

CVSS v2

Base Score: 6.6

Vector: CVSS2#AV:N/AC:H/Au:S/C:C/I:C/A:N

Severity: Medium

CVSS v3

Base Score: 6.8

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

Severity: Medium

CVSS v4

Base Score: 7.6

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

Severity: High

EPSS

EPSS: 0.00287