CVE-2026-24423

SmarterTools SmarterMail command injection, confirmed exploited in the wild.

SmarterTools SmarterMail contains a missing authentication for critical function vulnerability in the ConnectToHub API method. This could allow the attacker to point the SmarterMail instance to a malicious HTTP server which serves the malicious OS command and could lead to command execution.

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88%chance of exploitation in the next 30 days (EPSS), 99th percentile

5 Febadded to CISA's Known Exploited Vulnerabilities list, 2026

26 Febfederal remediation deadline, already passed

Passedpast the deadline: patch now

CISA's name for it	SmarterTools SmarterMail Missing Authentication for Critical Function Vulnerability
Vendor and product	SmarterTools · SmarterMail
Type	command injection · CWE-306
Exploited	Confirmed by CISA listed 5 February 2026
Likelihood	one of the most likely to be exploited of every vulnerability tracked
Deadline	26 February 2026 · already passed
Used in ransomware	Yes: CISA reports it used in ransomware campaigns
Advisories	www.smartertools.com ↗ · www.cve.org ↗ · nvd.nist.gov ↗

What to do

Three steps, in this order

Step 1

Apply the vendor fix; command injection on an exposed device is used within days of disclosure.

Step 2

Restrict the management interface to a trusted network until the fix is in.

Step 3

Review the device's logs and configuration for changes you did not make.

CISA's 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.

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Questions

CVE-2026-24423 in short

Is CVE-2026-24423 being exploited?

Yes. CISA added CVE-2026-24423 to its Known Exploited Vulnerabilities catalogue on 5 February 2026, which it does only on evidence of exploitation in the wild.

What is the CISA deadline for CVE-2026-24423?

US federal agencies must remediate it by 26 February 2026. Everyone else should treat that date as the latest safe point to patch an internet-facing system.

How likely is CVE-2026-24423 to be exploited in the next 30 days?

FIRST's Exploit Prediction Scoring System gives it 88%, the 99th percentile of every CVE it scores.

How do I fix CVE-2026-24423?

Apply the vendor fix; command injection on an exposed device is used within days of disclosure. Restrict the management interface to a trusted network until the fix is in. Review the device's logs and configuration for changes you did not make.

Same vendor

Other SmarterTools vulnerabilities being exploited

CVE	Product	Type	Listed
CVE-2025-52691	SmarterMail	remote code execution	26 January 2026
CVE-2026-23760	SmarterMail	authentication bypass	26 January 2026

Sources: CISA Known Exploited Vulnerabilities catalogue (released 10 November 2026) and FIRST EPSS. Page compiled automatically by SAK T.L.M, the threat-intelligence tool of SAK T.E.C, on 13 November 2026.