Vulnerability in Smartertools Smartermail

[ Description ]Official 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.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ Advisories ]Government CERT advisories

• BSI CERT-Bund11 Oct 2026WID-SEC-2026-3869

  SmarterTools SmarterMail: Multiple vulnerabilities Translated from German

  CVE-2026-104082CVE-2026-104083CVE-2026-104084

[ References ]References

• blog.evan.lat/posts/sm
• www.smartertools.com/smartermail/release-notes/current
• www.vulncheck.com/advisories/smartermail-build-9777-stale-jwt-role-claim-privilege-esca…