---
id: "CVE-2026-116786"
kind: "vulnerability"
aliases: ["CVE-2026-116786"]
title: "FreeSWITCH: SIP REFER injection lets a caller run OS commands"
severity: "high"
cvss: 8.8
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["freeswitch", "runtime", "self-hosted", "sip", "telecom", "voip"]
not_affected_if: ["no-sip-exposure", "version-1.11.2-or-later"]
published_at: "2026-11-05T20:17:45+00:00"
first_seen_at: "2026-11-05T20:40:45+00:00"
updated_at: "2026-11-05T20:42:55+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-116786", "first_seen_at": "2026-11-05T20:40:45+00:00"}]
exploit_sources: []
---

# FreeSWITCH: SIP REFER injection lets a caller run OS commands

FreeSWITCH builds an originate command from attacker-supplied SIP Refer-To values without escaping commas, so an injected variable can set an execute_on_originate action. An authenticated SIP caller on a bridged call can then run operating-system commands with the FreeSWITCH process privileges.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed version with `fs_cli -x version` or the FreeSWITCH package version, and compare against `1.11.2`.
- Confirm whether SIP REFER handling is active in the sofia profile configuration (REFER is enabled by default).
- Review whether external or registered SIP accounts can place calls that use off-box transfer.

## Fix

- FreeSWITCH: upgrade to `1.11.2`.

## Timeline

- 2026-11-05T20:40:45+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-116786

## Documents

- [advisory] Vendor advisory: github.com https://github.com/signalwire/freeswitch/security/advisories/GHSA-xjxm-9qx6-w3fj
- [fix] Patch: github.com https://github.com/signalwire/freeswitch/commit/fbac12b451a146fdac5104d25d337145be989e84
- [fix] Release notes: github.com https://github.com/signalwire/freeswitch/releases/tag/v1.11.2

## From the sources

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 1.11.2, sofia_handle_sip_i_refer() placed raw Refer-To URI parameters and headers inside a sip_invite_params channel-variable block passed to switch_ivr_originate(). The originate parser treated a comma in the attacker-controlled value as a variable separator, allowing an authenticated caller on a bridged call to inject arbitrary variables into a newly originated leg. An injected execute_on_originate value could invoke the system dialplan application before answer and execute operating-system commands with the FreeSWITCH process privileges. SIP REFER is enabled by default, and the sender needs only a registered account and a call that takes the off-box transfer path, not administrative or Event Socket access. This issue is fixed in version 1.11.2.

---

_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_