Uncontrolled Recursion in freeswitch - CVE-2026-49847
Published: June 4, 2026
Vulnerability identifier: #VU133314
CSH Severity: Medium
CVSS v4.0: 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/E:U/U:Green
CVE-ID: CVE-2026-49847
CWE-ID: CWE-674
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: www.freeswitch.org
Affected software:
freeswitch
freeswitch
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to uncontrolled recursion in the bundled cJSON parser in mod_verto when parsing deeply nested JSON in a WebSocket frame before authentication. A remote attacker can send a specially crafted WebSocket frame to cause a denial of service.
Any peer that can reach the WebSocket listener can trigger the issue without authentication or user interaction.
How to mitigate CVE-2026-49847
Install security update from vendor's website.