CVE-2026-23760: SmarterTools SmarterMail authentication bypass in password reset API

CVE-2026-23760 · Severity: critical · CVSS 9.8 · Exploited in the wild · Published 2026-01-22

SmarterMail, a popular enterprise email and collaboration server, contains a critical security flaw that allows unauthorized individuals to take over administrator accounts. By exploiting a weakness in the password reset system, an attacker can change the administrator's password without any existing credentials or special access. This grants the attacker full control over the email server, including the ability to read all user emails and execute commands on the underlying server hardware.

Technologies: SmarterTools SmarterMail. Vendors: SmarterTools.

Quick answers

Is CVE-2026-23760 exploited in the wild?
Yes. CVE-2026-23760 is known to be exploited in the wild, first recorded on 26 January 2026. Treat it as urgent.
How severe is CVE-2026-23760?
Critical severity, with a CVSS score of 9.8, published 22 January 2026.
Which products and versions are affected?
SmarterTools SmarterMail Prior to build 9511.
Is there a fix for CVE-2026-23760?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-23760 attacked?
It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-23760?
Check whether you run SmarterTools SmarterMail at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

An authentication bypass vulnerability (CWE-288) exists in the SmarterMail password reset API, specifically within the 'force-reset-password' endpoint. This endpoint permits anonymous requests and fails to validate an existing password or a valid reset token when targeting system administrator accounts. A remote, unauthenticated attacker can exploit this by submitting a target administrator username and a new password to the vulnerable endpoint. Successful exploitation results in full administrative compromise of the SmarterMail instance, which further allows for Remote Code Execution (RCE) with SYSTEM or root privileges via built-in management features. The vulnerability is addressed in SmarterMail build 9511.

Affected products

  • SmarterTools SmarterMail Prior to build 9511

Timeline

  • 2026-01-23: disclosed: Initial vulnerability details published by VulnCheck and researchers.
  • 2026-01-26: kev added: CISA added this vulnerability to the Known Exploited Vulnerabilities (KEV) catalog.
  • 2026-01-26: exploited: Vulnerability confirmed to be exploited in the wild.

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