CVE-2026-3551Network attack vector

Authenticated script execution via unescaped settings

Published Apr 16, 2026 · Updated Apr 16, 2026

Stored XSS in Custom New User Notification 1.2.0 and earlier allows remote authenticated users to run scripts in an administrator's browser. Its settings registration omits sanitize callbacks, while the settings page inserts get_option() values into HTML value attributes without esc_attr(). Administrator-level access is required; on multisite deployments, a subsite administrator can target a super administrator who opens that page.

CVSS severity4.4
Medium
EPSS probability0.36%
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 Custom New User Notification 1.2.0 and earlier allows remote authenticated users to run scripts in an administrator's browser. Its settings registration omits sanitize callbacks, while the settings page inserts get_option() values into HTML value attributes without esc_attr(). Administrator-level access is required; on multisite deployments, a subsite administrator can target a super administrator who opens that page.

The record

CVE
CVE-2026-3551
Published
Apr 16, 2026
Updated
Apr 16, 2026
Vendor
rafasashi
Product
Custom New User Notification
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Apr 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 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 <=1.2.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

rafasashi · Custom New User Notificationversion=0 <=1.2.0

Published CVSS scores

4.4WordfenceCVSS:3.1/AV:N/AC:H/PR:H/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.

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

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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007Command and Scripting Interpreter: JavaScript

Public exploit references

No public exploit references are available in this record.

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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