CVE-2026-107162 PUBLISHED

Express Gateway through 1.16.11 OAuth 2.0 Refresh Token Validation Bypass

Assigner: VulnCheck
Reserved: 07.10.2026 Published: 07.10.2026 Updated: 07.10.2026

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.

CVSS 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
CVSS Score: 7.6

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	High	Confidentiality	None
Attack Complexity	High	Integrity	High	Integrity	None
Attack Requirements	Present	Availability	None	Availability	None
Privileges Required	Low
User Interaction	None

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
CVSS Score: 6.8

Attack Vector	Network	Scope	Unchanged
Attack Complexity	High	Confidentiality Impact	High
Privileges Required	Low	Integrity Impact	High
User Interaction	None	Availability Impact	None

CVSS 3.1

Product Status

Vendor	ExpressGateway
Product	express-gateway
Versions	Default: unaffected affected from 0 to 1.16.11 (incl.)

CVE-2026-107162 PUBLISHED

Express Gateway through 1.16.11 OAuth 2.0 Refresh Token Validation Bypass

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Problem Types