CVE-2021-47888Public exploitNetwork attack vectorHinoki check available

Authenticated command execution via unrestricted PHP upload

Published Jan 23, 2026 · Updated Jan 23, 2026

Unrestricted file upload in Textpattern CMS before 4.8.3 allows remote authenticated users to execute arbitrary commands through PHP files. The Files panel's file_insert action accepts a PHP payload and stores it beneath the web-accessible /files path without blocking executable types. A logged-in account and valid anti-CSRF token are required; requesting the uploaded file runs its shell command with the web server's privileges.

CVSS severity8.7
High
EPSS probability0.64%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Unrestricted file upload in Textpattern CMS before 4.8.3 allows remote authenticated users to execute arbitrary commands through PHP files. The Files panel's file_insert action accepts a PHP payload and stores it beneath the web-accessible /files path without blocking executable types. A logged-in account and valid anti-CSRF token are required; requesting the uploaded file runs its shell command with the web server's privileges.

The record

CVE
CVE-2021-47888
Published
Jan 23, 2026
Updated
Jan 23, 2026
Vendor
Textpattern
Product
Textpattern CMS
Classifications
CWE-434, T1505.003, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 23, 2026Record 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.

  1. Affected versionversion=4.8.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Textpattern · Textpattern CMSversion=4.8.3

Published CVSS scores

8.7VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
8.8VulnCheckCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-434Unrestricted Upload of File with Dangerous Type
T1505.003Server Software Component Web Shell
T1190Exploit Public-Facing Application

Public exploit references

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