Integer underflow in freeswitch - CVE-2026-116569
Published: November 9, 2026
Vulnerability identifier: #VU162781
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-116569
CWE-ID: CWE-191
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows an unauthenticated remote attacker to crash the FreeSWITCH process and drop all active calls when a non-default MSRP listener is enabled.
The vulnerability exists due to unchecked unsigned subtraction in MSRP body parsing when a short received segment contains a byte range ending in an asterisk. An unauthenticated remote attacker can send a crafted message to the reachable MSRP port, triggering an out-of-bounds write before authentication without victim interaction.
Affected software
freeswitch
How to mitigate CVE-2026-116569
Install security update from vendor's website.
freeswitch - update to 1.11.2