FreeSWITCH: Pre-authentication bandwidth amplification via `mod_verto` speed-test frames_CVE-2026-49842

7.5 / 10

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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.

Basic Information

ID CVE-2026-49842

Source GitHub_M

Published Jun 9, 2026 at 16:02

Affected Product

Vendor signalwire

Product freeswitch

Version < 1.11.1

Affected Versions signalwire freeswitch < 1.11.1

CWE Classification

CWE-400

References

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    "published": "2026-06-09T16:02:58.096Z",
    "modified": "2026-06-09T16:02:58.096Z",
    "type": "cve",
    "title": "FreeSWITCH: Pre-authentication bandwidth amplification via `mod_verto` speed-test frames",
    "source": "GitHub_M",
    "references": "https://github.com/signalwire/freeswitch/security/advisories/GHSA-p3gx-p2w7-wp35\nhttps://github.com/signalwire/freeswitch/releases/tag/v1.11.1",
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