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CVE-2021-39201 - WordPress Core

CVE-2021-39201

WordPress is a free and open-source content management system written in PHP and paired with a MySQL or MariaDB database. ### Impact The issue allows an authenticated but low-privileged user (like contributor/author) to execute XSS in the editor. This bypasses the restrictions imposed on users who do not have the permission to post `unfiltered_html`. ### Patches This has been patched in WordPress 5.8, and will be pushed to older versions via minor releases (automatic updates). It's strongly recommended that you keep auto-updates enabled to receive the fix. ### References https://wordpress.org/news/category/releases/ https://hackerone.com/reports/1142140 ### For more information If you have any questions or comments about this advisory: * Open an issue in [HackerOne](https://hackerone.com/wordpress)

CVE-2021-39201

HIGH CVSS 7.6 Published 2021-09-09 Updated 2024-11-21
AI Risk Critical (100/100) Active Exploit: Likely Published Exploit: Public exploit references found Priority: P1 Immediate
Severity Band HIGH
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N
Affected Components 1
Reference Links 3
AI Risk Engine Critical (100/100)
Exploitability High
Active Exploitation Likely
Published Exploit Status Public exploit references found

Threat Timeline

  1. 2021-09-09 CVE published and first recorded in the threat feed.
  2. 2024-11-21 Record updated with latest vulnerability metadata.
  3. 2026-04-11 AI technical context refreshed for mitigation and impact guidance.
  4. Now Monitoring for follow-up changes, linked references, and new related CVEs.

AI Context

Machine-generated threat intelligence

AI Updated 6 days ago

AI enriched 6 days ago (2026-04-11 00:41 UTC)

Technical Summary

WordPress is a free and open-source content management system written in PHP and paired with a MySQL or MariaDB database. ### Impact The issue allows an authenticated but low-privileged user (like contributor/author) to execute XSS in the editor. This bypasses the restrictions imposed on users who do not have the permission to post `unfiltered_html`. ### Patches This has been patched in WordPress 5.8, and will be pushed to older versions via minor releases (automatic updates). It's strongly recommended that you…

Potential Impact

Severity is HIGH (CVSS 7.6). Depending on deployment context, affected components may be exposed to unauthorized actions or data integrity risk.

Exploitability Assessment

Exploitability is assessed as High based on published exploit references, remote code execution potential.

Primary risk drivers: published exploit references, remote code execution potential

Mitigation Recommendations

Validate affected product versions, prioritize patching, and monitor references for vendor remediation guidance. If immediate patching is not possible, apply compensating controls and limit exposure of vulnerable surfaces.

Detection & Monitoring

Track authentication anomalies, unexpected file writes, and suspicious plugin API activity around affected components.

Business Impact Lens

AI risk score 100/100 (Critical, High) with priority P1 Immediate. Prioritize remediation where affected components process customer data, admin sessions, or Internet-exposed workflows.

Affected Products

WordPress Core CORE · wordpress Affected: >= 5.0, < 5.8 Fixed in: 5.8
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