WebSocket Stack Overflow in FreeSWITCH by SignalWire
CVE-2026-49847

7.5HIGH

Key Information:

Vendor

Signalwire

Status
Freeswitch
Vendor
CVE Published:
9 June 2026

What is CVE-2026-49847?

FreeSWITCH, a Software Defined Telecom Stack, is susceptible to a stack overflow due to a malformed unauthenticated WebSocket frame containing a deeply nested JSON document. This flaw can lead to a crash of the FreeSWITCH process, severing all active calls and sessions. The recursion can disrupt the worker thread's stack execution, ultimately causing the process to terminate. Users are advised to update to version 1.11.1, where the issue has been resolved, to ensure uninterrupted service and mitigate potential exploitation.

Affected Version(s)

freeswitch < 1.11.1

References

https://github.com/signalwire/freeswitch/security/advisor...
x_refsource_CONFIRM
https://github.com/signalwire/freeswitch/releases/tag/v1....
x_refsource_MISC

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.