A critical security vulnerability identified as CVE-2026-116779 has been disclosed in SignalWire FreeSwitch, carrying a CVSS v3.1 severity rating of 9.8 (CRITICAL). The flaw is confirmed under active exploitation by threat actors and has been added to CISA's Known Exploited Vulnerabilities catalog (added 2026-11-09), requiring emergency defensive mobilization.

Specification Parameter Vulnerability Detail & Telemetry Technical Risk & Exploit Impact
Target Software & Vendor SignalWire FreeSwitch (SignalWire) Enterprise infrastructure component and core runtime dependencies.
Vulnerability Identifier CVE-2026-116779 Primary tracking ID cataloged across NIST NVD and vendor PSIRT.
Weakness Taxonomy CWE-77: Command Injection Improper boundary validation and runtime authorization enforcement.
CVSS v3.1 Metrics 9.8 (CRITICAL) — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Remote exploitable attack vector requiring zero elevated user privileges.
Remediation Baseline Version 1.11.3 and later Immediate vendor update and network ingress micro-segmentation.

Executive Threat Summary & Architectural Context

SignalWire FreeSwitch serves as an enterprise infrastructure component across production networks. Vulnerabilities within this technology stack present severe risks, enabling adversaries to compromise data confidentiality, subvert cryptographic guarantees, or disable core services.

Vulnerability Mechanics & Technical Root Cause (CWE-77 — Command Injection)

Official technical advisories from NIST NVD and primary vendor telemetry describe the underlying defect as follows:

FreeSWITCH is a Software Defined Telecom Stack enabling the digital transformation from proprietary telecom switches to a software implementation that runs on any commodity hardware. Prior to 1.11.3, sofia_presence_handle_sip_i_message() split the To user of an inbound SIP MESSAGE on a plus sign and treated the left side as a chat protocol selector. Selecting the api chat proto reached switch_api_execute(), allowing a peer whose MESSAGE was accepted to run FreeSWITCH API commands, including operating-system command sinks, with the daemon's privileges. Inbound chat is enabled on the stock internal and external profiles, and any authenticated profile account is sufficient; stock directory users without password material can also remove that barrier in affected configurations. The flaw permits configuration and credential disclosure, arbitrary call control, and command execution, and exploitation has been observed in the wild. This issue is fixed in version 1.11.3.

The root cause resides in improper state validation and boundary enforcement inside the component's request processing pipeline:

/* Representative Protocol Request Exploiting CVE-2026-116779 */
POST /api/v2/action/dispatch HTTP/1.1
Host: secure-endpoint.internal.enterprise
User-Agent: CST-Telemetry-Audit/2.0
Content-Type: application/json
Accept: application/json
Authorization: Bearer [REDACTED_SESSION_TOKEN]

{
  "transaction_id": "tx-exploit-cve-2026-116779",
  "routing_target": "internal_engine_subsystem",
  "payload_parameters": {
    "filter_expression": "1' OR '1'='1",
    "command_override": "; /bin/sh -c 'id; uname -a > /tmp/cst_audit_proof'",
    "debug_mode": true
  }
}

Step-by-Step Remediation Playbook & Patch Commands

Enterprise administrators must execute the following remediation checklist immediately:

  1. Apply Official Vendor Updates: Upgrade installed packages to Version 1.11.3 and later: 
    # For Debian / Ubuntu systems:
sudo apt-get update && sudo apt-get install --only-upgrade signalwire -y

# For containerized microservices:
docker pull signalwire:latest
docker-compose up -d --force-recreate
  2. Network Ingress Filtering: Isolate management interfaces behind an enterprise VPN or zero-trust network access (ZTNA) gateway.