CVE-2026-49841Network attack vector

Pre-auth heap corruption via oversized HTTP body

Published Jun 9, 2026 · Updated Jun 9, 2026

Heap-based buffer overflow in mod_verto in SignalWire FreeSWITCH before 1.11.1 allows remote attackers to corrupt heap memory via an HTTP POST body. The handler allocates a fixed 2 MiB buffer, accepts a Content-Length approaching 10 MiB, and bounds its body-read loop by that untrusted length. The path runs before HTTP basic authentication but requires a verto profile with a configured vhost; crafted body bytes can crash the service or corrupt adjacent heap data.

CVSS severity9.8
Critical
EPSS probability0.39%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-based buffer overflow in mod_verto in SignalWire FreeSWITCH before 1.11.1 allows remote attackers to corrupt heap memory via an HTTP POST body. The handler allocates a fixed 2 MiB buffer, accepts a Content-Length approaching 10 MiB, and bounds its body-read loop by that untrusted length. The path runs before HTTP basic authentication but requires a verto profile with a configured vhost; crafted body bytes can crash the service or corrupt adjacent heap data.

The record

CVE
CVE-2026-49841
Published
Jun 9, 2026
Updated
Jun 9, 2026
Vendor
SignalWire
Product
FreeSWITCH
Classifications
CWE-122, CWE-131, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 9, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.11.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

SignalWire · FreeSWITCHversion=< 1.11.1

Published CVSS scores

9.8GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-122Heap-based Buffer Overflow
CWE-131Incorrect Calculation of Buffer Size
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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