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OpenAdvisories
High · 8.8 CVE-2026-104084 EUVD-2026-95890GHSA-3wv9-x54m-xfch

SmarterMail < Build 9777 Stale JWT Role Claim Privilege Escalation via Refresh Token

Published Oct 9, 2026 · Updated Oct 27, 2026 · Assigned by VulnCheck

Description

SmarterMail before build 9777 contains a privilege escalation vulnerability where JWT access and refresh tokens embed a role claim at issuance that is not revalidated against the account's current role when redeemed through POST /api/v1/auth/refresh-token. Attackers who capture a refresh token issued before an administrator demotion, or a demoted user whose session was not actively polling at the time of demotion, can replay the stale token to obtain a new access token retaining the higher-privilege role (such as DomainAdmin or SysAdmin) until natural token expiry.

Affected products

VendorProductAffectedFixed
Smartertools Smartermail < Build 9777 Build 9777

Advisories 1

References