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

Published Jun 9, 2026
·
Updated

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 modverto 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 Software

2 affected components
FreeSWITCH FreeSWITCH<1.11.1
FreeSWITCH FreeSWITCH<1.11.1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade FreeSWITCH (mod_verto) to a version that resolves this vulnerability.

    Fixed in 1.11.1

Event History

Jun 9, 2026
CVE Published
via MITRE·04:02 PM
Data Sourced
via MITRE·04:02 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·05:17 PM
DescriptionSeverityWeaknessAffected Software
Free Weekly Intel

Don't miss critical vulnerabilities

Join thousands of security professionals who receive our weekly digest of trending CVEs, zero-days, and exploited vulnerabilities.

No spam. Unsubscribe anytime.

Frequently Asked Questions

1

What is the severity of CVE-2026-49841?

CVE-2026-49841 has a severity score of 9.8, indicating it is critical.

2

How do I fix CVE-2026-49841?

To fix CVE-2026-49841, upgrade to FreeSWITCH version 1.11.1 or later.

3

What type of vulnerability is CVE-2026-49841?

CVE-2026-49841 is a pre-authentication heap buffer overflow vulnerability.

4

What component is affected by CVE-2026-49841?

CVE-2026-49841 affects the mod_verto HTTP request handler in FreeSWITCH.

5

What impact does CVE-2026-49841 have on FreeSWITCH?

CVE-2026-49841 can lead to potential remote code execution and service disruption.

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203