CVE-2026-26930Public exploitNetwork attack vector

Reflected XSS via unsanitized MailboxId parameter

Published Feb 16, 2026 · Updated Feb 16, 2026

Reflected XSS in SmarterTools SmarterMail before 9526 allows remote attackers to execute script via crafted MAPI requests. The MAPI endpoints place the unneutralized MailboxId GET parameter into generated HTML, causing supplied script to run in the browser context. No authentication is required; execution is confined to the affected browser origin and its accessible session data.

CVSS severity7.2
High
EPSS probability0.31%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reflected XSS in SmarterTools SmarterMail before 9526 allows remote attackers to execute script via crafted MAPI requests. The MAPI endpoints place the unneutralized MailboxId GET parameter into generated HTML, causing supplied script to run in the browser context. No authentication is required; execution is confined to the affected browser origin and its accessible session data.

The record

CVE
CVE-2026-26930
Published
Feb 16, 2026
Updated
Feb 16, 2026
Vendor
SmarterTools Inc.
Product
SmarterMail
Classifications
CWE-79, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 16, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <9526

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

SmarterTools Inc. · SmarterMailversion=0 <9526

Published CVSS scores

7.2MITRECVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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