CVE-2024-0621Network attack vector

Stored XSS via unsanitized custom CSS

Published Feb 20, 2024 · Updated Apr 8, 2026

Stored XSS in Simple Share Buttons Adder 8.4.11 and earlier allows remote authenticated users to execute scripts through CSS settings. The plugin stores custom CSS from its administration settings without sufficient sanitization and renders it on pages without output escaping. Administrator-level access is required, and exposure is limited to multisite installations or sites where unfiltered_html is disabled; injected scripts run in a visitor's browser with that visitor's session privileges.

CVSS severity4.4
Medium
EPSS probability0.49%
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 Simple Share Buttons Adder 8.4.11 and earlier allows remote authenticated users to execute scripts through CSS settings. The plugin stores custom CSS from its administration settings without sufficient sanitization and renders it on pages without output escaping. Administrator-level access is required, and exposure is limited to multisite installations or sites where unfiltered_html is disabled; injected scripts run in a visitor's browser with that visitor's session privileges.

The record

CVE
CVE-2024-0621
Published
Feb 20, 2024
Updated
Apr 8, 2026
Vendor
Simple Share Buttons
Product
Simple Share Buttons Adder
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Feb 20, 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

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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 <=8.4.11

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Simple Share Buttons · Simple Share Buttons Adderversion=0 <=8.4.11

Published CVSS scores

4.4WordfenceCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N
4.8NVDCVSS:3.1/AV:N/AC:L/PR:H/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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

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