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

Should you act?

Exploited: patch now if you run it

CISA has confirmed exploitation in the wild. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• Yes, if you run SmarterTools SmarterMail. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2026-01-26, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2026-02-16; treat that as the outer limit, not the target. CISA also lists it as known to be used in ransomware campaigns.
• EPSS 96.4%, percentile 99.9: FIRST’s model estimates a 96.4% chance of exploitation activity in the next 30 days, higher than 99.9% of all scored CVEs (very high). EPSS is a probability, not a verdict.
• Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.

What it is

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.

CISA’s summary

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.

Weakness type: CWE-288.

Product: SmarterTools SmarterMail · Assigned by: VulnCheck · Published: 2026-01-22

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Attack requirements: none
• Privileges required: none (no login)
• User interaction: none

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: added 2026-01-26; federal due date 2026-02-16. Known ransomware use: Known.
• CISA required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
• CISA SSVC assessment: exploitation active, automatable yes, technical impact total.
• FIRST EPSS (model of 2026-10-21): 96.43% probability of exploitation activity in the next 30 days; percentile 99.9.

Timeline

• 2026-01-22 — CVE record published by VulnCheck
• 2026-01-26 — Added to CISA’s Known Exploited Vulnerabilities catalog
• 2026-02-16 — CISA remediation deadline for US federal agencies
• 2026-08-04 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vendor and project advisories, patches

1. smartertools.com smartertools.com

Vulnerability records

1. CVE.org record CVE-2026-23760 cve.org
2. NVD entry CVE-2026-23760 nvd.nist.gov

Government

1. CISA Known Exploited Vulnerabilities catalog entry cisa.gov

Other references from the CVE record and advisory

1. labs.watchtowr.com labs.watchtowr.com
2. code-white.com code-white.com
3. vulncheck.com vulncheck.com
4. huntress.com huntress.com

All exploited SmarterTools vulnerabilities · Today’s Security Digest