Stored XSS via unescaped block CSS class
Published Feb 6, 2023 · Updated Mar 25, 2025
Stored XSS in MonsterInsights before 8.12.1 allows remote authenticated users to execute JavaScript through crafted block options. The Inline Popular Posts block outputs the Additional CSS class option into a page or post without validating or escaping attacker-supplied attribute content. Contributor-level access is required to save the payload, and a visitor must interact with the rendered block to trigger code in that visitor's browser.
Summary
What happened
Stored XSS in MonsterInsights before 8.12.1 allows remote authenticated users to execute JavaScript through crafted block options. The Inline Popular Posts block outputs the Additional CSS class option into a page or post without validating or escaping attacker-supplied attribute content. Contributor-level access is required to save the payload, and a visitor must interact with the rendered block to trigger code in that visitor's browser.
The record
- CVE
- CVE-2023-0081
- Published
- Feb 6, 2023
- Updated
- Mar 25, 2025
- Vendor
- MonsterInsights
- Product
- MonsterInsights
- Classifications
- CWE-79, T1059.007
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 6, 2023CVE publishedPublication date reported by the CVE source.
- Mar 25, 2025Record 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.
- Affected versionversion=0 <8.12.1
What conditions does exploitation require?
What is affected?
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.
Weakness, pattern, technique
Public exploit references
- Inline Popular Posts Additional CSS class proof of conceptproof of concept · validated
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