CVE-2026-106621

Executive Summary

CVE-2026-106621 is a critical code injection vulnerability (CWE-94) in Adobe ColdFusion that permits unauthenticated remote attackers to execute arbitrary code in the context of the current user. With a CVSS v3.1 base score of 9.1, the flaw is network-reachable, requires no privileges and no user interaction, and yields a high impact on both confidentiality and integrity. Any internet-exposed or internally reachable ColdFusion deployment is a priority target, and because the vulnerability class is implicit code generation, exploitation typically results in full application-server compromise and potential lateral movement.

Technical Analysis

The vulnerability is classified under CWE-94, Improper Control of Generation of Code, commonly referred to as code injection. According to the NVD description, ColdFusion is affected by this flaw, and successful exploitation results in arbitrary code execution in the context of the current user. The attack is remote and requires no authentication or user interaction, as reflected in the CVSS vector (AV:N/AC:L/PR:N/UI:N). The scope is unchanged (S:U), while confidentiality and integrity impacts are both rated High; availability is rated None.

Code injection arises when an application constructs executable code, script, template logic, or expression strings from externally supplied input without adequate validation, sanitization, or escaping. Rather than treating attacker input as inert data, the application passes it into an interpreter or dynamic evaluation mechanism where it is parsed and executed. In the ColdFusion context, this class of weakness generally manifests in server-side processing paths that accept request data and subsequently evaluate it — for example, dynamic template evaluation, expression evaluation, or deserialization-adjacent code paths. These mechanics reflect the general behavior of the CWE-94 class and are not asserted as confirmed implementation specifics for this CVE.

The public intelligence provided does not disclose the precise vulnerable component, request parameter, endpoint, or function involved. The NVD description contains no URL paths, parameter names, or source-file references, and no CNA title was supplied by the assigning authority. Consequently, no specific code-level details — such as particular tags, functions, or API routes — can be confirmed from the available data. Analysts should treat the exact attack surface within ColdFusion as unconfirmed and rely on the vulnerability class, network reachability, and the pre-auth nature of the flaw when building detection and mitigation strategies.

The high integrity and confidentiality impacts follow directly from arbitrary code execution: the attacker effectively operates with the ColdFusion service account's permissions. Because the flaw is pre-authentication and network-facing, it represents a high-severity remote code execution exposure consistent with the 9.1 score. The availability metric of None indicates that exploitation is not expected to degrade service uptime directly, though an attacker could still choose to disrupt service after gaining code execution.

Exploitation Scenarios

Note: No public proof-of-concept, exploit code, or Nuclei template is available for CVE-2026-106621. The attack chain below is described strictly at the vulnerability-class level consistent with the CWE-94 classification and the NVD description. No specific endpoints, parameters, or function names are asserted, because none appear in the provided data.

1. Reconnaissance and target identification. An attacker identifies internet-exposed or internally reachable ColdFusion servers using standard host fingerprinting techniques. Shodan queries such as product:"ColdFusion" or http.title:"ColdFusion Administrator" are commonly used to enumerate candidate targets. The attacker confirms the target hosts a ColdFusion application and maps any reachable request-processing entry points.

2. Triggering the code injection flaw. The attacker crafts a request to a ColdFusion application entry point that accepts external input and, per the CWE-94 class, passes that input into a dynamic code generation or evaluation path. Because the flaw is pre-authentication (PR:N) and requires no user interaction (UI:N), no valid session or victim interaction is needed. The attacker supplies crafted input designed to break out of the intended data context and inject executable content.

3. Payload delivery and execution. At the vulnerability-class level, code injection allows the attacker's supplied content to be interpreted and executed by the ColdFusion server rather than treated as inert data. The specific execution primitive and transport are not disclosed in the available intelligence. The attacker's objective at this stage is to achieve arbitrary command or code execution in the security context of the ColdFusion service account.

4. Post-exploitation impact. Successful exploitation yields arbitrary code execution in the context of the current user. Consistent with the CVSS C:H/I:H impact ratings, the attacker can access and exfiltrate sensitive application data, configuration, and credentials, and can modify application logic or inject persistence. From an exposed ColdFusion server, attackers commonly pivot to internal systems using harvested credentials and configuration secrets, establish persistence, and deploy additional tooling. Availability is scored None (A:N), so service disruption is not an inherent outcome, though it remains possible at the attacker's discretion.

Impact Assessment

CVE-2026-106621 carries a CVSS v3.1 base score of 9.1 (Critical). The vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N indicates the following: network attack vector (remotely exploitable), low attack complexity (no special conditions required), no privileges required (pre-authentication), no user interaction required, unchanged scope, high confidentiality impact, high integrity impact, and no availability impact.

Business impact is severe. Arbitrary code execution in the ColdFusion service context can expose customer data, authentication secrets, application source, and integration credentials, triggering regulatory and contractual breach obligations (GDPR, HIPAA, PCI DSS, SOC 2) where regulated or payment data is processed. Integrity impact is high because attackers can alter application behavior, introduce malicious code, or tamper with records and transactions. The pre-auth, no-interaction nature means the blast radius extends to any ColdFusion instance reachable by the attacker, including internet-facing servers and internal hosts via lateral movement. The unchanged scope and A:N rating indicate the primary impact is confined to the compromised host and its data, with availability not inherently affected. Prioritize ColdFusion deployments with network exposure or that process sensitive data.

Detection Guidance

Sigma Rule

title: ColdFusion Code Injection Attempt - Suspicious Dynamic Code Input (CVE-2026-106621)
id: 8f3c1a2e-5b7d-4c9a-9e21-7d4f6a0b1c33
status: experimental
description: Detects suspicious request payloads targeting ColdFusion that may indicate attempts to exploit code injection (CWE-94) leading to arbitrary code execution. Behavior-based; specific endpoint unknown.
references:
  - https://nvd.nist.gov/vuln/detail/CVE-2026-106621
author: valtersit.com
date: 2026-01-01
tags:
  - attack.t1190
  - attack.execution
logsource:
  category: webserver
detection:
  selection_method:
    cs-method:
      - 'GET'
      - 'POST'
  selection_code_markers:
    - 'java.lang.Runtime'
    - 'ProcessBuilder'
    - 'getRuntime'
    - 'createObject('
    - 'cfexecute'
    - 'eval('
  selection_encoding:
    - '%00'
    - '${'
    - '#{'
  condition: selection_method and (selection_code_markers or selection_encoding)
falsepositives:
  - Legitimate developer testing against non-production ColdFusion instances
  - Security scanners issuing generic payload probes
level: high

YARA Rule

rule CVE_2026_106621_ColdFusion_CodeInjection
{
    meta:
        description = "Detects code-injection style payload artifacts associated with CVE-2026-106621 in ColdFusion request/response or log files"
        author = "valtersit.com"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-106621"
        date = "2026-01-01"
        severity = "critical"

    strings:
        $cf1 = "ColdFusion" nocase
        $inj1 = "java.lang.Runtime" nocase
        $inj2 = "ProcessBuilder" nocase
        $inj3 = "getRuntime().exec" nocase
        $inj4 = "createObject(" nocase
        $inj5 = "cfexecute" nocase
        $inj6 = "javax.script" nocase

    condition:
        $cf1 and 2 of ($inj*)
}

Suricata IDS Rule

alert http any any -> any any (msg:"CVE-2026-106621 ColdFusion Code Injection Attempt"; flow:established,to_server; content:"ColdFusion"; http_header; nocase; content:"java.lang.Runtime"; http_client_body; nocase; content:"getRuntime"; http_client_body; nocase; classtype:web-application-attack; reference:cve,2026-106621; reference:url,nvd.nist.gov/vuln/detail/CVE-2026-106621; sid:2026106621; rev:1;)

Elastic Detection

sequence by source.ip with maxspan=10s
  [network where network.protocol == "http" and
     http.request.method in ("GET", "POST") and
     url.path != null]
  [network where network.protocol == "http" and
     http.request.body.content : ("java.lang.Runtime" or "ProcessBuilder" or "getRuntime().exec" or "cfexecute")]

Splunk SPL Query

index=web sourcetype=coldfusion_access OR sourcetype=apache:access OR sourcetype=iis
| eval combined = lower(_raw)
| where (match(combined,"java\.lang\.runtime") OR match(combined,"processbuilder") OR match(combined,"getruntime\(\)\.exec") OR match(combined,"cfexecute") OR match(combined,"createobject\("))
| stats count min(_time) as first_seen max(_time) as last_seen values(uri) as uris by src_ip, host, status
| where count > 0
| sort - count

Wazuh OSSEC Rule

<group name="coldfusion,web,attack,">
  <rule id="100621" level="12">
    <if_sid>31100,31101,31103,31104,31108,31151,31161,31164</if_sid>
    <field name="url">java\.lang\.Runtime|ProcessBuilder|getRuntime\(\)\.exec|cfexecute</field>
    <description>CVE-2026-106621: Possible ColdFusion code injection attempt (CWE-94) detected in HTTP request</description>
    <mitre>
      <id>T1190</id>
    </mitre>
    <group>cve_2026_106621,</group>
  </rule>
</group>

Mitigation & Patch Guidance

Patch confidence: 0/4 (UNPATCHED — no patch evidence from any tracked source). No vendor fix, workaround, or affected version range has been identified. The following guidance is precautionary and should be validated against vendor advisories once available.

1. Immediate mitigations. Restrict network access to ColdFusion servers using firewall rules, ACLs, and reverse-proxy allowlists so that only trusted sources can reach application endpoints. Disable or block unused administrative interfaces and, where feasible, the ColdFusion Administrator from untrusted networks. Apply WAF rules or virtual patching that inspect and reject requests containing dynamic code-execution markers (for example Java runtime invocation patterns) targeted at ColdFusion entry points. Run the ColdFusion service under a low-privilege dedicated account with minimal filesystem and network permissions. Isolate ColdFusion hosts in segmented network zones to limit lateral movement. Monitor for anomalous outbound connections and unexpected child processes spawned by the ColdFusion service.

2. Patch and upgrade steps. No patch is currently available from any tracked source. Monitor Adobe's official security advisories and the NVD entry for CVE-2026-106621 continuously. When a vendor update is released, test in a staging environment and apply promptly to all ColdFusion instances, including those not directly internet-facing. Maintain an accurate inventory of all ColdFusion deployments and versions to ensure complete remediation coverage.

3. Long-term hardening. Keep ColdFusion and its underlying JVM and dependencies current with the latest supported releases. Enforce the principle of least privilege for the ColdFusion service account and any datasource credentials. Harden application input handling to avoid constructing executable code or dynamic expressions from untrusted input. Implement continuous vulnerability scanning and configuration assessment for all ColdFusion hosts. Retain and centrally aggregate web and application logs to support detection, hunting, and incident response. Include internet-facing ColdFusion servers in external attack-surface monitoring and threat-hunting cycles.

References

• NVD — CVE-2026-106621: https://nvd.nist.gov/vuln/detail/CVE-2026-106621
• MITRE CWE-94 — Improper Control of Generation of Code ('Code Injection'): https://cwe.mitre.org/data/definitions/94.html
• MITRE ATT&CK T1190 — Exploit Public-Facing Application: https://attack.mitre.org/techniques/T1190/
• Adobe Security Advisories (monitor for ColdFusion updates): https://helpx.adobe.com/security.html
• FIRST EPSS (score not yet available for this CVE): https://www.first.org/epss/

No public proof-of-concept, exploit code, or exploit-in-the-wild evidence was identified for CVE-2026-106621 at the time of writing. The vulnerability is not listed in CISA KEV. No threat actor campaigns have been attributed.