CVE-2026-48276: Adobe ColdFusion RCE Vulnerability

CVE-2026-48276 Overview

CVE-2026-48276 is an Unrestricted Upload of File with Dangerous Type vulnerability affecting Adobe ColdFusion 2025.9, 2023.20, and earlier versions. The flaw allows a remote, unauthenticated attacker to upload files with dangerous types and achieve arbitrary code execution in the context of the current user. Exploitation requires no user interaction and results in a changed scope, meaning the compromise extends beyond the vulnerable component. The weakness is classified under CWE-434 and carries a maximum CVSS 3.1 base score. Adobe published fixes in security bulletin APSB26-68.

Critical Impact
Unauthenticated remote attackers can upload malicious files to vulnerable ColdFusion servers and execute arbitrary code, leading to full server compromise across trust boundaries.

Affected Products

Adobe ColdFusion 2025 (through Update 9)
Adobe ColdFusion 2023 (through Update 20)
Earlier ColdFusion releases sharing the affected upload handling logic

Discovery Timeline

2026-06-30 - CVE-2026-48276 published to NVD
2026-07-01 - Last updated in NVD database

Technical Details for CVE-2026-48276

Vulnerability Analysis

CVE-2026-48276 stems from ColdFusion accepting file uploads without adequately restricting the file type. An attacker sends a crafted HTTP request to an exposed ColdFusion endpoint and places a file whose type or extension allows server-side execution. Because the server processes the uploaded content in the context of the current user, the attacker gains code execution with the ColdFusion service account's privileges.

The scope change reflected in the CVSS vector indicates the impact crosses the security authority of the vulnerable component. A successful upload can pivot into adjacent systems, files, and data stores that the ColdFusion process can reach. Internet-exposed instances are the primary risk surface because the network attack vector requires no authentication or user interaction.

Root Cause

The root cause is missing or insufficient validation on the file type accepted by the ColdFusion upload handler. Server-side logic fails to reject files with dangerous extensions or executable content, and the uploaded artifact lands in a location where the application engine will parse and run it.

Attack Vector

Remote attackers reach the vulnerable component over HTTP or HTTPS. After identifying an exposed ColdFusion instance, the attacker submits a POST request containing a payload with an executable extension such as a ColdFusion Markup (.cfm) or ColdFusion Component (.cfc) file. Requesting the uploaded file triggers server-side execution. No credentials or user interaction are required.

// No verified proof-of-concept code is publicly available for CVE-2026-48276.
// Refer to the Adobe Security Advisory APSB26-68 for vendor-authored technical details.

Detection Methods for CVE-2026-48276

Indicators of Compromise

Unexpected .cfm, .cfc, .jsp, or .class files appearing in ColdFusion web-accessible directories, particularly within cfusion/wwwroot or custom upload paths.
HTTP POST requests to file-upload endpoints from unfamiliar external IP addresses followed by GET requests to the same uploaded filename.
ColdFusion or JVM child processes spawning shells (cmd.exe, powershell.exe, /bin/sh) or network utilities.
Outbound connections from the ColdFusion service account to unknown hosts shortly after an upload event.

Detection Strategies

Inspect ColdFusion access and application logs for POST requests to upload handlers followed by requests to newly created files with executable extensions.
Alert on the ColdFusion service process writing files with server-executable extensions outside expected deployment workflows.
Correlate web server events with endpoint process creation to identify command execution originating from the ColdFusion Java process.

Monitoring Recommendations

Enable verbose logging for the ColdFusion administrator and file upload endpoints, then forward logs to a centralized platform for retention and analytics.
Monitor filesystem changes in web roots and instance directories using file integrity monitoring.
Track outbound network activity from ColdFusion hosts and alert on connections to non-approved destinations.

How to Mitigate CVE-2026-48276

Immediate Actions Required

Apply the updates published in Adobe Security Advisory APSB26-68 to ColdFusion 2025 and ColdFusion 2023 immediately.
Restrict network exposure of the ColdFusion Administrator and file upload endpoints to trusted management networks only.
Audit web-accessible directories for unauthorized .cfm, .cfc, and .jsp files created on or before patch installation.
Rotate credentials and secrets accessible to the ColdFusion service account if compromise is suspected.

Patch Information

Adobe released fixed builds for ColdFusion 2025 and ColdFusion 2023 as documented in bulletin APSB26-68. Administrators should install the vendor-supplied update matching their installed release train and confirm the update level in the ColdFusion Administrator after deployment. Follow Adobe's post-installation lockdown guide to reduce residual attack surface.

Workarounds

Place ColdFusion behind a web application firewall with rules that block requests uploading files with server-executable extensions.
Configure the web server or reverse proxy to deny direct requests to uploaded file directories and disallow execution of content in upload paths.
Run ColdFusion under a least-privilege service account with restricted filesystem and network permissions to limit blast radius.

bash

# Example: block execution in an uploads directory on Apache fronting ColdFusion
<Directory "/var/www/coldfusion/uploads">
    Options -ExecCGI
    <FilesMatch "\.(cfm|cfc|cfml|jsp|jspx)$">
        Require all denied
    </FilesMatch>
</Directory>