What’s Vulnerable › Vulnerabilities

CVE-2026-49841: FreeSWITCH: Pre-authentication heap buffer overflow in `mod_verto` HTTP POST body read

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-09 · updated 2026-07-23
• Weakness: CWE-122

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

• signalwire freeswitch: before 1.11.1 — fixed in 1.11.1

How to fix

Upgrade to a fixed version: signalwire freeswitch 1.11.1. Check the vendor advisory for mitigations.

References

• https://github.com/signalwire/freeswitch/releases/tag/v1.11.1
• https://github.com/signalwire/freeswitch/security/advisories/GHSA-wfrq-qvg2-f88f

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