Vulnerability · Published Jun 9, 2026 · Assigned by GitHub_M

CVE-2026-49847FreeSWITCH: Stack overflow in bundled cJSON parser via deeply nested JSON

High 7.5

In plain English

A high-severity security flaw in freeswitch from signalwire. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 36% of all known vulnerabilities).

Severity (CVSS 3.1)7.5High

Exploit odds (30 days)0.4%top 64.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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 version 1.11.1, a single unauthenticated WebSocket frame containing a deeply nested JSON document crashes the FreeSWITCH process via stack overflow, terminating all calls and sessions on the host. The recursion drives the worker thread's stack pointer into the stack guard page, raising SIGSEGV from the kernel before any usable write primitive develops. This issue has been patched in version 1.11.1.

Affected products (as reported)

Vendor	Product	Versions
signalwire	freeswitch	< 1.11.1

Weakness: CWE-674 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

https://github.com/signalwire/freeswitch/security/advisories/GHSA-2v74-pcgh-75wg x_refsource_CONFIRM
https://github.com/signalwire/freeswitch/releases/tag/v1.11.1 x_refsource_MISC