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CVE-2021-29447 - WordPress Core

CVE-2021-29447

Wordpress is an open source CMS. A user with the ability to upload files (like an Author) can exploit an XML parsing issue in the Media Library leading to XXE attacks. This requires WordPress installation to be using PHP 8. Access to internal files is possible in a successful XXE attack. This has been patched in WordPress version 5.7.1, along with the older affected versions via a minor release. We strongly recommend you keep auto-updates enabled.

CVE-2021-29447

HIGH CVSS 7.1 Published 2021-04-15 Updated 2024-11-21
AI Risk Critical (97/100) 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:N/S:U/C:H/I:L/A:N
Affected Components 1
Reference Links 7
AI Risk Engine Critical (97/100)
Exploitability High
Active Exploitation Likely
Published Exploit Status Public exploit references found

Threat Timeline

  1. 2021-04-15 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 00:42 UTC)

Technical Summary

Wordpress is an open source CMS. A user with the ability to upload files (like an Author) can exploit an XML parsing issue in the Media Library leading to XXE attacks. This requires WordPress installation to be using PHP 8. Access to internal files is possible in a successful XXE attack. This has been patched in WordPress version 5.7.1, along with the older affected versions via a minor release. We strongly recommend you keep auto-updates enabled.

Potential Impact

Severity is HIGH (CVSS 7.1). 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 97/100 (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: >= 5.6.0, < 5.7.1 Fixed in: 5.7.1

References

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