CVE-2026-49842
HIGHFreeSWITCH: Pre-authentication bandwidth amplification via `mod_verto` speed-test frames
Title source: cnaDescription
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.
References (2)
Core 2
Core References
X_Refsource_Confirm x_refsource_confirm
https://github.com/signalwire/freeswitch/security/advisories/GHSA-p3gx-p2w7-wp35
X_Refsource_Misc x_refsource_misc
https://github.com/signalwire/freeswitch/releases/tag/v1.11.1
Scores
CVSS v3
7.5
EPSS
0.0045
EPSS Percentile
35.5%
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-400
Status
published
Products (2)
freeswitch/freeswitch
< 1.11.1
signalwire/freeswitch
< 1.11.1
Published
Jun 09, 2026
Tracked Since
Jun 09, 2026