FreeSWITCH: Channel-variable injection via SIP REFER leads to command execution in mod_sofia
Affects FreeSWITCH SIP profiles that accept REFER, the default, when a REFER names a dialog the instance does not hold. Fixed in 1.11.2.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 1.11.2
- Who is exposed
- Specific setups only
Do first: Check whether your setup matches what the bug needs. A SIP profile that accepts REFER, which is the default. The REFER names a dialog the instance does not hold, so the transfer takes the off-box originate path.
- Last modified
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 17/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
FreeSWITCH's mod_sofia module mishandles SIP REFER transfer requests, letting injected call variables carry operating-system commands. A remote attacker who holds only a registered SIP account can reach the flaw over the network without any user action and run commands with the privileges of the FreeSWITCH process.
Read the original description
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.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure8/25Specific setups only, reachable over the network
- Reach?/20Unknown. No tracked technology or package matched
- Severity8.8/10CVSS 8.8
- No patch0/5No signal
What would change the score
- Would score about 67 if added to CISA KEV
- Would score about 62 if CISA's SSVC rates exploitation active
- Would score about 24 if CISA's SSVC rates it automatable
What to do
Check whether your setup matches what the bug needs.
A SIP profile that accepts REFER, which is the default. The REFER names a dialog the instance does not hold, so the transfer takes the off-box originate path.Upgrade to a fixed version: 1.11.2.
Workaround: Set <param name="disable-transfer" value="true"/> on the affected profile.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- signalwire freeswitch
fixed in 1.11.2
Evidence 3
- Advisory
- Repository
- Repository
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-116786
Is CVE-2026-116786 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
A SIP REFER can inject arbitrary channel variables into an originated call leg, including execute_on_originate, which runs the system dialplan application. That gives OS command execution as the FreeSWITCH process user.Source: github.com
Which versions are affected by CVE-2026-116786?
freeswitch: before 1.11.2.Source: cve.now feed data
Am I affected, and how do I check?
Versions before 1.11.2 are affected in SIP profiles that accept REFER, which is the default, when a REFER names a dialog the instance does not hold so the transfer takes the off-box originate path. To check a setup, look at the version reported by FreeSWITCH and at whether the SIP profile sets disable-transfer to true.Source: github.com
How do I fix CVE-2026-116786?
Upgrade FreeSWITCH to 1.11.2 or later. Until the upgrade is done, set disable-transfer to true on the affected SIP profile.Source: github.com