CVE-2026-34634: ColdFusion SSRF Vulnerability

CVE-2026-34634 Overview

Adobe ColdFusion contains a Server-Side Request Forgery (SSRF) vulnerability [CWE-918] that can lead to privilege escalation. An unauthenticated attacker can send crafted requests over the network to coerce the ColdFusion server into issuing requests to attacker-chosen destinations. The scope is changed, meaning successful exploitation impacts resources beyond the vulnerable component itself. Exploitation does not require user interaction, which lowers the barrier for mass scanning and automated attacks against exposed ColdFusion instances.

Critical Impact
Unauthenticated network attackers can abuse ColdFusion as a request proxy to reach internal systems, access cloud metadata services, and escalate privileges across trust boundaries.

Affected Products

Adobe ColdFusion (versions listed in Adobe Security Advisory APSB26-144)
Deployments exposing the ColdFusion web interface to untrusted networks
ColdFusion servers hosted in cloud environments with instance metadata services reachable

Discovery Timeline

2026-10-13 - CVE-2026-34634 published to the National Vulnerability Database
2026-10-14 - Last updated in NVD database

Technical Details for CVE-2026-34634

Vulnerability Analysis

The flaw is classified as a Server-Side Request Forgery [CWE-918]. ColdFusion accepts user-supplied input that influences the destination of a server-initiated HTTP request without sufficient validation. Attackers supply URLs that point to internal services, loopback addresses, or cloud metadata endpoints the ColdFusion host can reach. Because the attack vector is network-based and requires no authentication or user interaction, exploitation can be automated at scale.

The advisory notes a changed scope, indicating that the impacted resources extend beyond the ColdFusion process itself. In practice, SSRF against application servers frequently yields privilege escalation by harvesting cloud instance credentials, bypassing network segmentation, or interacting with unauthenticated internal management APIs.

Root Cause

The root cause is missing or inadequate validation of URL inputs used by ColdFusion to initiate outbound requests. The server trusts attacker-controllable destinations and executes requests on their behalf, inheriting the ColdFusion process network position and any associated identity.

Attack Vector

Exploitation proceeds over the network against an exposed ColdFusion endpoint. The attacker submits a request containing a URL or hostname that the vulnerable handler fetches. Targets typically include cloud metadata services such as 169.254.169.254, internal admin consoles, localhost services bound only to the loopback interface, and reachable private-range hosts. Successful requests can disclose credentials or trigger state-changing actions that escalate privileges.

No verified proof-of-concept code is public at the time of writing. Refer to the Adobe Security Advisory APSB26-144 for authoritative technical details.

Detection Methods for CVE-2026-34634

Indicators of Compromise

Outbound HTTP requests from ColdFusion hosts to cloud metadata endpoints such as 169.254.169.254 or metadata.google.internal
ColdFusion-initiated connections to internal private IP ranges that do not match normal application traffic
Unexpected requests to localhost or loopback-bound administrative services originating from ColdFusion worker processes
Spikes in outbound DNS lookups from ColdFusion servers for attacker-controlled domains

Detection Strategies

Baseline normal ColdFusion outbound traffic and alert on connections to RFC1918, link-local, and metadata ranges
Inspect web server access logs for request parameters containing URL schemes (http://, file://, gopher://) targeting internal hosts
Correlate ColdFusion process network activity with cloud IAM credential issuance or temporary token use
Deploy network detection rules that identify SSRF-style payloads referencing internal IP space in HTTP request bodies and query strings

Monitoring Recommendations

Centralize ColdFusion application and web server logs for retrospective hunting on URL parameters
Monitor cloud audit logs (AWS CloudTrail, Azure Activity Log, GCP Audit Logs) for API calls originating from ColdFusion instance identities
Track egress firewall denies from ColdFusion subnets to catch exploitation attempts blocked by network controls

How to Mitigate CVE-2026-34634

Immediate Actions Required

Apply the ColdFusion updates referenced in Adobe Security Advisory APSB26-144 on all affected hosts
Inventory internet-exposed ColdFusion instances and prioritize patching for externally reachable systems
Enforce Instance Metadata Service Version 2 (IMDSv2) on AWS and equivalent hardened metadata configurations on other clouds
Review cloud IAM roles attached to ColdFusion hosts and remove any permissions beyond what the application requires

Patch Information

Adobe has published fixes in Security Advisory APSB26-144. Administrators should consult the advisory for exact version numbers and update packages applicable to their ColdFusion release train, then validate the installed build after patching.

Workarounds

Restrict ColdFusion outbound connectivity using egress firewall rules that block RFC1918, loopback, and cloud metadata address ranges
Place ColdFusion behind a web application firewall configured with SSRF detection signatures
Terminate TLS and apply URL allowlisting at an upstream proxy for any application features that make outbound HTTP requests
Isolate ColdFusion into a dedicated network segment with no direct route to sensitive internal management interfaces

bash

# Example egress restriction (iptables) blocking cloud metadata and private ranges
iptables -A OUTPUT -m owner --uid-owner coldfusion -d 169.254.169.254 -j REJECT
iptables -A OUTPUT -m owner --uid-owner coldfusion -d 10.0.0.0/8 -j REJECT
iptables -A OUTPUT -m owner --uid-owner coldfusion -d 172.16.0.0/12 -j REJECT
iptables -A OUTPUT -m owner --uid-owner coldfusion -d 192.168.0.0/16 -j REJECT
iptables -A OUTPUT -m owner --uid-owner coldfusion -d 127.0.0.0/8 -j REJECT