CVE-2026-49841

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

State: Published
Severity: 9.8 Critical
Published: Jun 9, 2026
Updated: Jun 11, 2026
Reserved: Jun 1, 2026

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, 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.

Scores

CVSS	Score	Vector	Source
3.1	9.8 Critical	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H	GitHub_M

Weaknesses

CWE-122 Heap-based Buffer Overflow
CWE-131 Incorrect Calculation of Buffer Size

Affected Products

Product	Versions
freeswitchsignalwire	< 1.11.1Affected

References

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