# CVE-2026-49841: SignalWire FreeSWITCH heap overflow in mod_verto HTTP POST handler

Source: https://junglewise.ai/threats/cve-2026-49841-signalwire-freeswitch-heap-overflow-in-mod-verto-http-post  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-09. Updated: 2026-06-09  
License: CC BY 4.0 with a link back

CVE-2026-49841 · Severity: critical · CVSS 9.8 · Published 2026-06-09

FreeSWITCH is an open-source telecommunications platform used to handle voice, video, and messaging traffic. A critical vulnerability in its 'mod_verto' component allows an unauthenticated attacker to crash the service or potentially take control of the server by sending a specially crafted web request. This could lead to a total service outage, unauthorized access to communication data, or a foothold for further attacks on the corporate network.

Technologies: [SignalWire FreeSWITCH](https://junglewise.ai/threats/technologies/freeswitch). Vendors: [SignalWire](https://junglewise.ai/threats/vendors/signalwire).

## Quick answers

**Is CVE-2026-49841 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-49841 being exploited in the wild.

**How severe is CVE-2026-49841?** Critical severity, with a CVSS score of 9.8, published 9 June 2026.

**Which products and versions are affected?** SignalWire FreeSWITCH <= 1.11.0.

**Is there a fix for CVE-2026-49841?** A patch was published on 2026-05-26: Version 1.11.1 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-49841 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-49841?** Check whether you run SignalWire FreeSWITCH at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A heap-based buffer overflow exists in the mod_verto HTTP request handler of FreeSWITCH. The component allocates a fixed 2 MiB buffer for 'application/x-www-form-urlencoded' POST bodies but permits a Content-Length of up to 10 MiB. Because the body-read loop is bounded by the Content-Length header rather than the allocated buffer size, an unauthenticated remote attacker can trigger an overflow of approximately 8 MiB. This occurs before HTTP basic authentication is processed. Exploitation can lead to immediate denial of service via heap corruption, information disclosure, or remote code execution. The vulnerability is reachable only when at least one <vhost> is configured in the verto profile. A fix is available in version 1.11.1.

## Affected products

- SignalWire FreeSWITCH <= 1.11.0

## Timeline

- 2026-05-26: patched: Version 1.11.1 released
- 2026-06-03: advisory: GitHub Security Advisory published
- 2026-06-09: disclosed: CVE published to NVD

## References

- [https://github.com/signalwire/freeswitch/releases/tag/v1.11.1](https://github.com/signalwire/freeswitch/releases/tag/v1.11.1)
- [https://github.com/signalwire/freeswitch/security/advisories/GHSA-wfrq-qvg2-f88f](https://github.com/signalwire/freeswitch/security/advisories/GHSA-wfrq-qvg2-f88f)

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