CVE-2026-49841CWE-122CWE-131

FreeSWITCH: Pre-authentication heap buffer overflow in `mod_verto` HTTP POST body read

Critical · published June 9, 2026

CVSS v3.1
9.8
EPSS
1%
Percentile
48.3
In the wild
Unconfirmed
What it is

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, the mod_verto HTTP request handler allocates a fixed 2 MiB buffer for a POST application/x-www-form-urlencoded body but accepts Content-Length up to just under 10 MiB. The body-read loop is bounded by Content-Length rather than the buffer size, producing an attacker-controlled heap overflow of up to ~8 MiB -- before the HTTP basic-auth check runs. This issue has been patched in version 1.11.1.

The record
Technical detail
CVSS v3.1
9.8 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00605 · 48.3th percentile
Weaknesses
CWE-122 · Heap-based Buffer Overflow; CWE-131 · Incorrect Calculation of Buffer Size
Published
2026-06-09T16:02Z
EPSS history
Timeline
  • 09 JUN 16:02Z
    FreeSWITCH: Pre-authentication heap buffer overflow in `mod_verto` HTTP POST body read
    cvelistv5