CVE-2021-36899Network attack vector

Administrator-session script execution

Published Oct 11, 2022 · Updated Apr 28, 2026

Reflected XSS in Gabe Livan's Asset CleanUp plugin 1.3.8.4 and earlier allows remote authenticated users to run scripts in an administrator's browser. Public records describe insufficient input sanitization and output escaping but do not identify the affected parameter or request handler. Exploitation requires Administrator privileges and user interaction, and successful execution can read or alter browser-accessible data in the administrator's session without interrupting service.

CVSS severity4.8
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

Reflected XSS in Gabe Livan's Asset CleanUp plugin 1.3.8.4 and earlier allows remote authenticated users to run scripts in an administrator's browser. Public records describe insufficient input sanitization and output escaping but do not identify the affected parameter or request handler. Exploitation requires Administrator privileges and user interaction, and successful execution can read or alter browser-accessible data in the administrator's session without interrupting service.

The record

CVE
CVE-2021-36899
Published
Oct 11, 2022
Updated
Apr 28, 2026
Vendor
Gabe Livan
Product
Asset CleanUp: Page Speed Booster
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Oct 11, 2022CVE 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=<= 1.3.8.4 <=1.3.8.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Gabe Livan · Asset CleanUp: Page Speed Boosterversion=<= 1.3.8.4 <=1.3.8.4

Published CVSS scores

4.8PatchstackCVSS: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')
T1059.007Command 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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