by Kastro
Paper/Archive/CVE-2026-49841

CVE-2026-49841

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

EPSS 0.4%CVSS 9.8
critical.is priorityof 100
36
CVSS 9.8 (CNA)9.8 / 10 × 3029.4Not in CISA KEV+300.0EPSS percentile 33.7.337 × 206.7No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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

ProductAffectedFixed inSource
freeswitch< 1.11.1–CNA

Scores by source

GitHub_M (CNA)9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total

References

refgithub.com/signalwire/freeswitch/security/advisories/GHSA-wfrq-qvg2-f88frefgithub.com/signalwire/freeswitch/releases/tag/v1.11.1