CVE-2026-126969VulnerabilityPublished 13 Nov 2026

ZDI-26-997: SmarterTools SmarterMail Insufficient Entropy Authentication Bypass Vulnerability

Source Zero Day Initiative

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Not known to be exploited.

Data as of 13 Nov 2026, 22:19 UTC

Severity

Critical

Rated Critical by Zero Day Initiative · CVSS not yet scored by NVD

Exploitation evidence

Disclosed: evidence found.
Public on cve.org; its publication date is not in this record
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 13 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

AI-suggested

Until a patch is available, monitor vendor communications for updates.

Description

A critical vulnerability in SmarterTools SmarterMail allows remote attackers to bypass authentication without requiring any credentials. This flaw enables unauthorized access to affected installations, posing a significant security risk.

Impact

Successful exploitation allows remote attackers to bypass authentication controls, potentially leading to unauthorized access to the SmarterMail system. This could compromise sensitive information and system integrity. No known exploits in the wild have been reported.

Summary

The vulnerability identified as CVE-2026-126969 affects SmarterTools SmarterMail and permits remote attackers to bypass authentication mechanisms due to insufficient entropy in the authentication process. Exploitation does not require prior authentication, making it a severe security issue. The Zero Day Initiative assigned a CVSS rating of 9.1, indicating high severity.

References

zerodayinitiative.com/advisories/ZDI-26-997/ (opens in a new tab)

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