CVE-2026-41904Public exploitNetwork attack vector

Customer email script execution via validator-sink mismatch

Published May 7, 2026 · Updated May 7, 2026

Stored XSS in FreeScout before 1.8.217 allows remote authenticated users to execute script in customers' email clients via auto-replies. autoReplySave validates a tag-stripped copy but stores the original input after an attribute-blind tag blocklist, and the email template renders it unescaped. The updateAutoReply permission and an HTML-capable recipient are required; successful exploitation exposes the recipient's webmail context.

CVSS severity7.6
High
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in FreeScout before 1.8.217 allows remote authenticated users to execute script in customers' email clients via auto-replies. autoReplySave validates a tag-stripped copy but stores the original input after an attribute-blind tag blocklist, and the email template renders it unescaped. The updateAutoReply permission and an HTML-capable recipient are required; successful exploitation exposes the recipient's webmail context.

The record

CVE
CVE-2026-41904
Published
May 7, 2026
Updated
May 7, 2026
Vendor
FreeScout
Product
FreeScout
Classifications
CWE-79, T1203
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 7, 2026CVE publishedPublication date reported by the CVE source.
  2. May 7, 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=< 1.8.217

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

FreeScout · FreeScoutversion=< 1.8.217

Published CVSS scores

7.6GitHubCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1203Exploitation for Client Execution

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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