CVE-2026-49843 Details
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, mod_verto's JSON-RPC handler bound the connection to the client-supplied sessid on the first frame, before the authentication gate. Binding inserts the connection into the global session hash and, on a key collision, drops the prior occupant of that slot — sending it a verto.punt, detaching its calls, and closing its socket. An unauthenticated network attacker who knows a target session UUID could therefore evict the legitimate client. This issue has been patched in version 1.11.1.
A vulnerability in FreeSWITCH's mod_verto component, affecting versions through 1.11.0, allows an unauthenticated network attacker to evict a legitimate client from a WebSocket session. This is achieved by exploiting the JSON-RPC handler, which binds the connection to a client-supplied session ID before authentication. The binding process can cause session collisions, leading to the disconnection of the original session. The vulnerability requires knowledge of the target session UUID and is present in deployments with an accessible mod_verto WebSocket listener.
Users are advised to upgrade to FreeSWITCH version 1.11.1 or later. If the upgrade is not immediately possible, mod_verto can be disabled or the WebSocket listener restricted to trusted networks.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Jun 10, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/signalwire/freeswitch/releases/tag/v1.11.1 | [email protected] | Release Notes |
| https://github.com/signalwire/freeswitch/security/advisories/GHSA-9457-fxr9-x78m | [email protected] | Third Party Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-287 | Improper Authentication | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| freeswitch freeswitch | < 1.11.1 |
CPE
Remediation
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Change History
5 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 23, 2026 | CVE Translated | [email protected] |
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Jun 10, 2026 | Initial Analysis | [email protected] |
| Jun 9, 2026 | New CVE Received | [email protected] |