---
id: CVE-2026-104084
title: >-
  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/…
summary: >-
  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/…
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-613
published: '2026-10-09'
updated: '2026-10-09'
sourceUpdated: '2026-10-09T20:17:09.050'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-104084'
references:
  - url: >-
      https://www.smartertools.com/smartermail/release-notes/current#/9526:~:text=Build%209777%20(Oct%208%2C%202026)
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/smartermail-build-9777-stale-jwt-role-claim-privilege-escalation-via-refresh-token
    label: disclosure@vulncheck.com
tags:
  - nvd
ingestedAt: '2026-10-09T17:04:42.806Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.