---
title: "CVE-2026-104084: SmarterMail - Privilege Escalation"
description: "SmarterMail < 9777 contains a privilege escalation caused by JWT tokens embedding role claims that are not revalidated on refresh, letting attackers retain higher privileges by replaying stale tokens, exploit requires captured refresh token."
url: https://panop.io/threat-heartbeat/CVE-2026-104084/
---

# CVE-2026-104084 SmarterMail - Privilege Escalation

SmarterMail < 9777 contains a privilege escalation caused by JWT tokens embedding role claims that are not revalidated on refresh, letting attackers retain higher privileges by replaying stale tokens, exploit requires captured refresh token.

CVSS base score 8.8 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Required

EPSS

0.27% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-104084)

## Details

Type

Privilege Escalation

Impact

Privilege Escalation

CVSS vector

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

Published

9 October 2026

Updated

15 October 2026

Weakness

[CWE-613](https://cwe.mitre.org/data/definitions/613.html)

## Vendor fix

Update to build 9777 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-104084](https://nvd.nist.gov/vuln/detail/CVE-2026-104084)
- [https://blog.evan.lat/posts/sm/](https://blog.evan.lat/posts/sm/)
- [https://www.smartertools.com/smartermail/release-notes/current#/9526:~:text=Build%209777%20(Oct%208%2C%202026)](https://www.smartertools.com/smartermail/release-notes/current#/9526:~:text=Build%209777%20%28Oct%208%2C%202026%29)
- [https://www.vulncheck.com/advisories/smartermail-build-9777-stale-jwt-role-claim-privilege-escalation-via-refresh-token](https://www.vulncheck.com/advisories/smartermail-build-9777-stale-jwt-role-claim-privilege-escalation-via-refresh-token)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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