FreeSWITCH: Pre-authentication out-of-bounds write in MSRP message body parsing
Only FreeSWITCH 1.11.1 and earlier with an MSRP listener enabled is affected. The fix is 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. Affected versions are 1.11.1 and earlier (FreeSWITCH before 1.11.2). An MSRP listener must be enabled by setting a listen port (listen-port or listen-ssl-port) in msrp.conf.xml.
- 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? →
- 20/100 · 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, a software telecom switching stack, contains a memory-corruption flaw in its MSRP message parsing that a remote attacker can trigger without logging in, crashing the service and dropping all active calls. Remote code execution has not been demonstrated.
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, msrp_parse_buffer() subtracted delimiter framing from a peer-controlled short segment whose MSRP byte range ended in * without first proving the segment was long enough. The unsigned result wrapped near SIZE_MAX and reached switch_msrp_msg_set_payload() as both an allocation size and memcpy length, while related pointer arithmetic could read before the receive buffer. The listener is disabled by default in msrp.conf.xml, but any deployment enabling an MSRP TCP or TLS port parses this framing before authentication. An unauthenticated network peer can corrupt memory and crash FreeSWITCH, dropping all active calls, although remote code execution has not been demonstrated. This issue is fixed in version 1.11.2.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure12/25Specific setups only, reachable over the network without a login
- Reach?/20Unknown. No tracked technology or package matched
- Severity7.5/10CVSS 7.5
- No patch0/5No signal
What would change the score
- Would score about 70 if added to CISA KEV
- Would score about 65 if CISA's SSVC rates exploitation active
What to do
Check whether your setup matches what the bug needs.
Affected versions are 1.11.1 and earlier (FreeSWITCH before 1.11.2). An MSRP listener must be enabled by setting a listen port (listen-port or listen-ssl-port) in msrp.conf.xml.Upgrade to a fixed version: 1.11.2.
Workaround: Comment out listen-port and listen-ssl-port in msrp.conf.xml to stop the listener, or restrict listen-ip and the port at the firewall.
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-2026-116569
Is CVE-2026-116569 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?
The MSRP message body parser writes outside its buffer before any authentication happens. A remote sender can crash the FreeSWITCH process, which drops all active calls. Remote code execution has not been demonstrated.Source: github.com
Which versions are affected by CVE-2026-116569?
freeswitch: before 1.11.2.Source: cve.now feed data
Am I affected, and how do I check?
FreeSWITCH 1.11.1 and earlier are affected, but only when an MSRP listener is enabled by setting listen-port or listen-ssl-port in msrp.conf.xml. To check, look at the installed FreeSWITCH version and whether either setting is present in msrp.conf.xml.Source: github.com
How do I fix CVE-2026-116569?
Upgrade to FreeSWITCH 1.11.2 or later. Until then, comment out listen-port and listen-ssl-port in msrp.conf.xml, or restrict listen-ip and the port at the firewall.Source: github.com