CVE-2023-5109Network attack vector

Stored XSS via unsanitized shortcode attributes

Published Oct 20, 2023 · Updated Apr 8, 2026

Stored cross-site scripting in WP Mailto Links – Protect Email Addresses 3.1.3 and earlier allows remote authenticated users to inject scripts. The wpml_mailto shortcode stores user-supplied attributes without sufficient input sanitization or output escaping, causing attacker-controlled markup to render in pages. Contributor-level access is required to create the payload, and the script executes in the browser of any user who visits the injected page.

CVSS severity6.4
Medium
EPSS probability0.42%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored cross-site scripting in WP Mailto Links – Protect Email Addresses 3.1.3 and earlier allows remote authenticated users to inject scripts. The wpml_mailto shortcode stores user-supplied attributes without sufficient input sanitization or output escaping, causing attacker-controlled markup to render in pages. Contributor-level access is required to create the payload, and the script executes in the browser of any user who visits the injected page.

The record

CVE
CVE-2023-5109
Published
Oct 20, 2023
Updated
Apr 8, 2026
Vendor
Online Optimisation
Product
WP Mailto Links – Protect Email Addresses
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 20, 2023CVE publishedPublication date reported by the CVE source.
  2. Apr 8, 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 <=3.1.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Online Optimisation · WP Mailto Links – Protect Email Addressesversion=0 <=3.1.3

Published CVSS scores

6.4WordfenceCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/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
Privilegesauthenticated
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/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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