CVE-2023-51374Network attack vector

Stored XSS via unescaped admin settings

Published Dec 29, 2023 · Updated Apr 28, 2026

Stored XSS in ZeroBounce Email Verification & Validation 1.0.11 and earlier allows remote authenticated users to execute browser scripts. The plugin's admin settings accept values without sufficient input sanitization and later render them without output escaping. Administrator-level access is required, and exploitation is limited to WordPress multisite installations or sites where unfiltered_html is disabled.

CVSS severity5.9
Medium
EPSS probability0.33%
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 ZeroBounce Email Verification & Validation 1.0.11 and earlier allows remote authenticated users to execute browser scripts. The plugin's admin settings accept values without sufficient input sanitization and later render them without output escaping. Administrator-level access is required, and exploitation is limited to WordPress multisite installations or sites where unfiltered_html is disabled.

The record

CVE
CVE-2023-51374
Published
Dec 29, 2023
Updated
Apr 28, 2026
Vendor
ZeroBounce
Product
ZeroBounce Email Validation
Classifications
CWE-79, CAPEC-592, T1059.007
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Dec 29, 2023CVE publishedPublication date reported by the CVE source.
  2. Apr 28, 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=n/a <=1.0.11 changes=[{"at":"1.0.12","status":"unaffected"}]

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

ZeroBounce · ZeroBounce Email Validationversion=n/a <=1.0.11 changes=[{"at":"1.0.12","status":"unaffected"}]

Published CVSS scores

5.5WordfenceCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N
5.9PatchstackCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:L

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')
CAPEC-592Stored XSS
T1059.007Command and Scripting Interpreter: JavaScript/JScript

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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