CVE-2026-48307: Adobe ColdFusion XSS Vulnerability

CVE-2026-48307 Overview

Adobe ColdFusion contains a reflected Cross-Site Scripting (XSS) vulnerability affecting versions 2025.9, 2023.20, and earlier. An attacker can inject malicious scripts into a web page rendered by the vulnerable ColdFusion server. Successful exploitation can lead to arbitrary code execution in the context of the current user's browser session. The flaw requires user interaction, as the victim must open a crafted malicious link. The scope is changed [CWE-79], meaning the injected payload can affect resources beyond the vulnerable component.

Critical Impact
A successful attack can result in arbitrary code execution in the victim's browser context, enabling session theft, credential harvesting, and unauthorized actions against the ColdFusion application.

Affected Products

Adobe ColdFusion 2025 (including updates 1 through 9, and base release)
Adobe ColdFusion 2023 (including updates 1 through 20, and base release)
Any ColdFusion 2025.9, 2023.20, and earlier deployments

Discovery Timeline

2026-06-30 - CVE-2026-48307 published to NVD
2026-07-01 - Last updated in NVD database

Technical Details for CVE-2026-48307

Vulnerability Analysis

The vulnerability is a reflected Cross-Site Scripting flaw classified under [CWE-79], Improper Neutralization of Input During Web Page Generation. ColdFusion fails to properly sanitize user-controlled input before reflecting it back into HTTP responses. An attacker crafts a URL containing JavaScript payloads embedded in request parameters. When a victim clicks the link, the ColdFusion server echoes the payload into the response, causing the browser to execute it in the application's origin. The changed scope indicator means the injected script executes with privileges that extend beyond the immediate vulnerable component, potentially reaching other browser contexts or downstream services.

Root Cause

The root cause is missing or insufficient output encoding on server-side response generation. ColdFusion reflects request parameters directly into HTML, JavaScript, or attribute contexts without applying context-aware encoding. Without functions such as EncodeForHTML(), EncodeForJavaScript(), or EncodeForHTMLAttribute(), attacker-supplied markup escapes its intended data context and becomes executable code.

Attack Vector

Exploitation requires adjacent network access and user interaction. The attacker delivers a malicious link through phishing, chat, or a compromised page. When the victim, ideally an authenticated administrator or user, clicks the link, the injected payload runs in the ColdFusion application's origin. The payload can read cookies, exfiltrate session tokens, perform CSRF-style actions, or pivot to further attacks against the administrator console.

No verified proof-of-concept code has been published. Refer to the Adobe ColdFusion Security Advisory APSB26-68 for vendor guidance.

Detection Methods for CVE-2026-48307

Indicators of Compromise

HTTP request parameters containing <script>, javascript:, onerror=, or onload= patterns reflected in ColdFusion responses.
Web server access logs showing URL-encoded script payloads such as %3Cscript%3E or %3Cimg%20src%3D targeting ColdFusion endpoints.
Outbound HTTP requests from user browsers to attacker-controlled domains immediately after visiting a ColdFusion application URL.

Detection Strategies

Deploy Web Application Firewall (WAF) rules to inspect query strings and POST bodies for XSS payload signatures targeting ColdFusion .cfm and /CFIDE/ paths.
Correlate web proxy telemetry with endpoint browser process activity to identify script execution originating from ColdFusion domains.
Review ColdFusion server logs for anomalous parameter values, particularly long strings containing HTML tags or JavaScript event handlers.

Monitoring Recommendations

Enable verbose HTTP request logging on the ColdFusion connector and forward logs to a centralized SIEM.
Monitor administrator account activity for unexpected configuration changes that could indicate a session hijack via XSS.
Alert on referrer headers pointing to external domains when internal ColdFusion administrative endpoints are accessed.

How to Mitigate CVE-2026-48307

Immediate Actions Required

Apply the Adobe security updates referenced in APSB26-68 to ColdFusion 2025 and ColdFusion 2023 installations.
Restrict access to the ColdFusion Administrator interface to trusted management networks only.
Rotate authentication cookies and administrative credentials if suspicious reflected payloads have been observed in logs.

Patch Information

Adobe published the fix in security bulletin APSB26-68. Administrators should upgrade to a version later than ColdFusion 2025.9 and ColdFusion 2023.20 as directed by the vendor. Review the Adobe ColdFusion Security Advisory for exact update package details and installation instructions.

Workarounds

Deploy WAF signatures that block reflected XSS payloads containing <script>, event handlers, and JavaScript URI schemes against ColdFusion endpoints.
Configure Content-Security-Policy response headers to restrict inline script execution and limit script sources to trusted origins.
Set the HttpOnly and Secure flags on ColdFusion session cookies to reduce token theft impact if XSS executes.
Educate privileged users to avoid clicking untrusted links that reference internal ColdFusion hostnames or IPs.

bash

# Example CSP header configuration in ColdFusion Application.cfc
<cfset cfheader name="Content-Security-Policy"
                value="default-src 'self'; script-src 'self'; object-src 'none'; frame-ancestors 'none'">
<cfset cfheader name="X-XSS-Protection" value="1; mode=block">
<cfset cfheader name="X-Content-Type-Options" value="nosniff">