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Critical · 9.8 CVE-2026-49841 EUVD-2026-35472

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

Published Jun 9, 2026 · Updated Jun 11, 2026 · Assigned by GitHub_M

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.

Affected products

VendorProductAffectedFixed
signalwire freeswitch < 1.11.1 —

References