CVE-2026-75999 Overview
CVE-2026-75999 is an Improper Input Validation vulnerability [CWE-20] in Adobe ColdFusion that enables arbitrary code execution in the context of the current user. A low-privileged attacker on an adjacent network can trigger the flaw when a victim opens a malicious file. The vulnerable component sits within an administrative network zone by default, which limits the attack surface but does not eliminate risk. Successful exploitation changes scope, allowing impact beyond the vulnerable component itself. Adobe published a security advisory tracked as APSB26-119 addressing this issue.
Critical Impact
Arbitrary code execution in the current user context with scope change, enabling lateral impact across trust boundaries on ColdFusion servers.
Affected Products
- Adobe ColdFusion (versions listed in advisory APSB26-119)
- ColdFusion administrative components exposed within administrative network zones
- Environments where users open ColdFusion files from untrusted sources
Discovery Timeline
- 2026-09-08 - CVE-2026-75999 published to the National Vulnerability Database
- 2026-09-09 - Last updated in the NVD database
Technical Details for CVE-2026-75999
Vulnerability Analysis
CVE-2026-75999 stems from improper input validation within Adobe ColdFusion. The application accepts input without adequately verifying its structure, type, or content before processing. When ColdFusion parses a crafted file, the malformed input reaches an execution path and triggers arbitrary code execution in the current user context.
The vulnerability requires user interaction. A victim with access to the administrative network zone must open a malicious file for exploitation to succeed. Because the scope is changed, code executed through the vulnerable component can affect resources beyond ColdFusion's own security boundary.
Root Cause
The root cause is a failure to enforce input validation on data consumed by ColdFusion, mapped to [CWE-20]. Missing or insufficient checks allow attacker-controlled content to influence execution flow. Adobe's advisory APSB26-119 addresses the validation gap through updated parsing and sanitization logic.
Attack Vector
Exploitation requires adjacent network access and low privileges on the target environment. The attacker delivers a malicious file to a user who has legitimate access to the ColdFusion administrative zone. When the victim opens the file, ColdFusion processes attacker-controlled input, and arbitrary code executes with the victim's privileges. See the Adobe ColdFusion Security Advisory for parameter and component specifics.
// No verified proof-of-concept code is publicly available.
// Refer to Adobe advisory APSB26-119 for technical guidance.
Detection Methods for CVE-2026-75999
Indicators of Compromise
- Unexpected child processes spawned by ColdFusion service accounts (cfusion, jrun, or Java runtime processes)
- ColdFusion server writing or executing files outside standard application directories
- Anomalous inbound file transfers to hosts within the ColdFusion administrative network zone
- Outbound network connections from ColdFusion processes to unknown external hosts
Detection Strategies
- Monitor process creation events where the parent process is a ColdFusion or Java runtime binary and the child is a shell, script interpreter, or LOLBin
- Alert on file write events by ColdFusion service accounts to system paths, startup folders, or web-accessible directories
- Inspect ColdFusion request logs for uploads or references to unusual file types processed by the administrative interface
Monitoring Recommendations
- Enable process, file, and network telemetry on ColdFusion hosts and forward to a centralized analytics platform
- Track authentication and access events for administrative network zones to identify compromised low-privileged accounts
- Correlate ColdFusion service behavior with user file-open activity to surface interactive exploitation chains
How to Mitigate CVE-2026-75999
Immediate Actions Required
- Apply the patch referenced in Adobe advisory APSB26-119 to all ColdFusion instances
- Restrict access to the ColdFusion administrative network zone to a minimal set of authenticated users
- Instruct administrators and developers not to open ColdFusion files received from untrusted sources
- Audit ColdFusion service accounts and reduce their operating system privileges where feasible
Patch Information
Adobe released fixes through security bulletin APSB26-119. Administrators should review the Adobe ColdFusion Security Advisory for the exact versions, update packages, and installation instructions applicable to their deployment.
Workarounds
- Enforce network segmentation so only administrative subnets can reach ColdFusion management components
- Apply application allowlisting to block unauthorized child processes launched by the ColdFusion runtime
- Disable or restrict features that parse untrusted file formats until the patch is deployed
# Example: restrict access to ColdFusion admin interface with iptables
iptables -A INPUT -p tcp --dport 8500 -s 10.10.20.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 8500 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
