What is the CVSS score of CVE-2021-47888?

CVE-2021-47888 has a CVSS 3.1 base score of 8.8 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.5%.

Which versions of PHP are affected by CVE-2021-47888?

Textpattern CMS versions 4.8.3 and earlier contain a critical file upload vulnerability that allows attackers to upload and execute malicious files, potentially compromising web applications and…

Is there a public PoC exploit available for CVE-2021-47888?

Yes, a public proof-of-concept exploit is available for CVE-2021-47888. Prioritise patching immediately. EPSS: 0.5%.

How to fix or mitigate CVE-2021-47888?

Within 24 hours: Inventory all Textpattern installations and identify those running version 4.8.3 or earlier; disable file upload functionality if business operations permit. Within 7 days: Upgrade to version 4.8.4 or later if available, or migrate to an alternative CMS platform; implement WAF rules to block suspicious file uploads. Within 30 days: Complete migration away from affected versions; conduct forensic audit of upload directories and logs for indicators of compromise; implement file type validation and execution prevention controls.

PHP CVE-2021-47888

HIGH

Unrestricted Upload of File with Dangerous Type (CWE-434)

2026-01-23 disclosure@vulncheck.com

PHP RCE

8.8

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

8.8 HIGH

AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 21:54 vuln.today

PoC Detected

Jan 26, 2026 - 15:03 vuln.today

Public exploit code

CVE Published

Jan 23, 2026 - 17:15 nvd

HIGH 8.8

DescriptionCVE.org

Textpattern versions prior to 4.8.3 contain an authenticated remote code execution vulnerability that allows logged-in users to upload malicious PHP files. Attackers can upload a PHP file with a shell command execution payload and execute arbitrary commands by accessing the uploaded file through a specific URL parameter.

AnalysisAI

Textpattern versions up to 4.8.3 is affected by unrestricted upload of file with dangerous type (CVSS 8.8).

Technical ContextAI

This vulnerability (CWE-434: Unrestricted Upload of File with Dangerous Type) exists in the a specific URL component. Textpattern versions prior to 4.8.3 contain an authenticated remote code execution vulnerability that allows logged-in users to upload malicious PHP files. Attackers can upload a PHP file with a shell command execution payload and execute arbitrary commands by accessing the uploaded file through a specific URL parameter.

Affected ProductsAI

Product: Textpattern. Versions: up to 4.8.3. Component: a specific URL.

RemediationAI

Monitor vendor advisories for a patch. Validate file types by content. Store uploads outside web root. Restrict network access to the affected service where possible.