Known exploited vulnerability · CISA KEV

CVE-2026-23760: SmarterTools SmarterMail Authentication Bypass Using an Alternate Path or Channel Vulnerability

SmarterTools SmarterMail contains an authentication bypass using an alternate path or channel vulnerability in the password reset API. The force-reset-password endpoint permits anonymous requests and fails to verify the existing password or a reset token when resetting system administrator accounts. This could allow an unauthenticated attacker to supply a target administrator username and a new password to reset the account, resulting in full administrative compromise of the SmarterMail instance.

CVE-2026-23760

Exploited in the wild. Fix this first.

CISA added it to the Known Exploited Vulnerabilities catalog on 2026-01-26: attackers are using it right now. It is known to be used in ransomware campaigns.

CISA KEV: Listed; Added 2026-01-26 · federal fix-by 2026-02-16
EPSS (30 days): 96%; Higher than 99.9% of CVEs · 2026-11-01
CVSS v4.0: 9.3 Critical; CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

What CISA says

SmarterTools SmarterMail Authentication Bypass Using an Alternate Path or Channel Vulnerability

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

NVD description · published 2026-01-22

SmarterTools SmarterMail versions prior to build 9511 contain an authentication bypass vulnerability in the password reset API. The force-reset-password endpoint permits anonymous requests and fails to verify the existing password or a reset token when resetting system administrator accounts. An unauthenticated attacker can supply a target administrator username and a new password to reset the account, resulting in full administrative compromise of the SmarterMail instance. NOTE: SmarterMail system administrator privileges grant the ability to execute operating system commands via built-in management functionality, effectively providing administrative (SYSTEM or root) access on the underlying host.

Full record on NVD

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How to check if you are exposed to CVE-2026-23760

Find every SmarterTools SmarterMail system you or your clients run, including ones exposed to the internet. Those come first: CISA only lists flaws attackers are already using.
Compare each version with the fixed versions in the vendor advisory below. Where no fix exists yet, apply the vendor’s mitigation or take the system off the internet.
Run a credentialed vulnerability scan to catch the systems you missed, then check that the next scan no longer reports CVE-2026-23760.

US federal agencies had to fix this by 2026-02-16. Everyone else should treat that deadline as a guide: if it has passed, this is overdue.

Affected versions

Versions the National Vulnerability Database lists as vulnerable to CVE-2026-23760. Check the vendor advisory for the exact fixed builds before you sign anything off.

Product	Vulnerable versions
SmarterTools Smartermail	before 100.0.9511

Timeline

2026-01-22 · Published in the National Vulnerability Database
2026-01-26 · Added to CISA's Known Exploited Vulnerabilities catalog, 4 days after it was published
2026-02-16 · Fix-by date for US federal agencies, passed 258 days ago

Vendor advisories and fixes

https://www.smartertools.com/smartermail/release-notes/current

Weakness type

CWE-288

More exploited SmarterTools vulnerabilities

CISA lists 3 exploited SmarterTools vulnerabilities. The closest matches:

Keep going

Sources: CISA Known Exploited Vulnerabilities catalog (version 2026.10.30); EPSS data from FIRST.org; CVSS and descriptions from the NIST National Vulnerability Database. Checked 2026-11-01. This product uses the NVD API but is not endorsed or certified by the NVD.