CVE-2026-49847

HIGH

FreeSWITCH: Stack overflow in bundled cJSON parser via deeply nested JSON

Title source: cna

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.

References (2)

Core 2

Core References

X_Refsource_Confirm x_refsource_confirm

https://github.com/signalwire/freeswitch/security/advisories/GHSA-2v74-pcgh-75wg

X_Refsource_Misc x_refsource_misc

https://github.com/signalwire/freeswitch/releases/tag/v1.11.1

Scores

CVSS v3 7.5

EPSS 0.0041

EPSS Percentile 32.8%

Attack Vector NETWORK

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment

Exploitation none

Automatable yes

Technical Impact partial

Details

CWE

CWE-674

Status published

Products (2)

freeswitch/freeswitch < 1.11.1

signalwire/freeswitch < 1.11.1

Published Jun 09, 2026

Tracked Since Jun 09, 2026