CVE-2025-4611Network attack vector

Stored XSS via unescaped breadcrumb shortcode attributes

Published May 21, 2025 · Updated Apr 8, 2026

Stored XSS in the Slim SEO breadcrumbs shortcode through 4.5.3 allows remote authenticated users to inject scripts through attributes. The render_shortcode method places the user-controlled separator into breadcrumb markup without HTML escaping; other breadcrumb fields also lacked contextual escaping. Contributor-level access is required, and the stored script executes in the browser of any user who opens the injected page.

CVSS severity6.4
Medium
EPSS probability0.50%
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 the Slim SEO breadcrumbs shortcode through 4.5.3 allows remote authenticated users to inject scripts through attributes. The render_shortcode method places the user-controlled separator into breadcrumb markup without HTML escaping; other breadcrumb fields also lacked contextual escaping. Contributor-level access is required, and the stored script executes in the browser of any user who opens the injected page.

The record

CVE
CVE-2025-4611
Published
May 21, 2025
Updated
Apr 8, 2026
Vendor
Anh Tran
Product
Slim SEO
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 21, 2025CVE 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 <=4.5.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Anh Tran · Slim SEOversion=0 <=4.5.3

Published CVSS scores

6.4WordfenceCVSS:3.1/AV:N/AC:L/PR:L/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
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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