CVE-2024-4891Network attack vector

Stored XSS via unescaped Advanced Heading tagName

Published May 18, 2024 · Updated Apr 8, 2026

Stored XSS in Essential Blocks for Gutenberg 4.5.12 and earlier allows remote authenticated users to inject scripts through tagName. AdvancedHeading.php places the user-controlled tagName value into an HTML element name without sufficient sanitization or output escaping. Contributor-level access is required to save a crafted Advanced Heading block, and the script executes when a visitor opens the affected page.

CVSS severity6.4
Medium
EPSS probability0.47%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Stored XSS in Essential Blocks for Gutenberg 4.5.12 and earlier allows remote authenticated users to inject scripts through tagName. AdvancedHeading.php places the user-controlled tagName value into an HTML element name without sufficient sanitization or output escaping. Contributor-level access is required to save a crafted Advanced Heading block, and the script executes when a visitor opens the affected page.

The record

CVE
CVE-2024-4891
Published
May 18, 2024
Updated
Apr 8, 2026
Vendor
ReviewX Team
Product
Essential Blocks for Gutenberg
Classifications
CWE-79, T1203
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 18, 2024CVE 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=4.5.12

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

ReviewX Team · Essential Blocks for Gutenbergversion=0 <=4.5.12

Published CVSS scores

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

Weakness, pattern, technique

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

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo