CVE-2026-49842

FreeSWITCH: Pre-authentication bandwidth amplification via `mod_verto` speed-test frames

HIGH
7.5
CVSS Score
Published: June 9, 2026 at 04:02 PM UTC
Updated: July 23, 2026 at 07:32 PM UTC
2 products affected across 2 vendorsFreeswitchFreeswitch

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Severity
HIGH7.5
Exploit prediction
EPSS 0.4%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.11.1
Affected range stops below 1.11.1, so it looks safe — our inference, not a vendor statement
v < 1.11.1
Affected range stops below 1.11.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (2)

x_refsource_CONFIRMThird Party Advisory
Source: cverecord
https://github.com/signalwire/freeswitch/security/advisories/GHSA-p3gx-p2w7-wp35
x_refsource_MISCRelease Notes
Source: cverecord
https://github.com/signalwire/freeswitch/releases/tag/v1.11.1

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-400

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