CVE-2026-49847

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

HIGH
7.5
CVSS Score
Published: June 9, 2026 at 04:05 PM UTC
Updated: July 23, 2026 at 07:32 PM UTC
2 products affected across 2 vendorsFreeswitchFreeswitch

Using freeswitch by signalwire?

Get instant alerts when new vulnerabilities affect freeswitch - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
HIGH7.5
Exploit prediction
EPSS 0.4%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.11.1
Affected range stops below 1.11.1, so it looks safe — our inference, not a vendor statement
v < 1.11.1
Affected range stops below 1.11.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (2)

x_refsource_CONFIRMThird Party Advisory
Source: cverecord
https://github.com/signalwire/freeswitch/security/advisories/GHSA-2v74-pcgh-75wg
x_refsource_MISCRelease Notes
Source: cverecord
https://github.com/signalwire/freeswitch/releases/tag/v1.11.1

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-674

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card