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 WebSocket frame loop intercepts a #-prefixed speed-test protocol (#SPU / #SPB / #SPE) before any authentication check. The declared payload size in #SPU was parsed with atoi() and only rejected non-positive values, so an unauthenticated peer could request up to INT_MAX bytes. The server then wrote roughly size * 10 bytes back during the download phase, on the order of 20 GB per request, yielding strong outbound bandwidth amplification from a short request. This issue has been patched in version 1.11.1.
History

Wed, 10 Jun 2026 15:15:00 +0000

Type Values Removed Values Added
First Time appeared Freeswitch
Freeswitch freeswitch
CPEs cpe:2.3:a:freeswitch:freeswitch:*:*:*:*:*:*:*:*
Vendors & Products Freeswitch
Freeswitch freeswitch

Tue, 09 Jun 2026 19:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 09 Jun 2026 18:00:00 +0000

Type Values Removed Values Added
First Time appeared Signalwire
Signalwire freeswitch
Vendors & Products Signalwire
Signalwire freeswitch

Tue, 09 Jun 2026 16:30:00 +0000

Type Values Removed Values Added
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 WebSocket frame loop intercepts a #-prefixed speed-test protocol (#SPU / #SPB / #SPE) before any authentication check. The declared payload size in #SPU was parsed with atoi() and only rejected non-positive values, so an unauthenticated peer could request up to INT_MAX bytes. The server then wrote roughly size * 10 bytes back during the download phase, on the order of 20 GB per request, yielding strong outbound bandwidth amplification from a short request. This issue has been patched in version 1.11.1.
Title FreeSWITCH: Pre-authentication bandwidth amplification via `mod_verto` speed-test frames
Weaknesses CWE-400
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-06-09T16:02:58.096Z

Updated: 2026-06-09T18:39:33.710Z

Reserved: 2026-06-01T18:50:36.057Z

Link: CVE-2026-49842

cve-icon Vulnrichment

Updated: 2026-06-09T18:23:04.850Z

cve-icon NVD

Status : Analyzed

Published: 2026-06-09T17:17:48.017

Modified: 2026-06-10T15:06:33.640

Link: CVE-2026-49842

cve-icon Redhat

No data.