CVE-2026-49841
FreeSWITCH, a software telecom stack, had a critical heap overflow bug in its mod_verto HTTP handler. The flaw allowed attackers to send a large POST body that exceeded the allocated buffer, causing a memory corruption before authentication. The issue was fixed in FreeSWITCH 1.11.1.
An official fix is available, so this entry is kept for 30 days and then removed automatically.
Who is affected
FreeSWITCH installations running any version earlier than 1.11.1, typically used by telecom operators and service providers.
Real-world impact
An attacker could send a specially crafted request to overflow the server’s heap, potentially crashing the service or executing arbitrary code, leading to denial of service or full system compromise.
Why this severity
The CVSS score of 9.8 reflects that the vulnerability is exploitable over the network with no authentication, no user interaction, and grants full confidentiality, integrity, and availability impact.
What to do about it
- 01Upgrade FreeSWITCH to version 1.11.1 or later.
- 02Restart the FreeSWITCH service to apply the update.
NVD-referenced vendor advisory
Timeline
- Jun 9, 2026 · Jun 9, 2026PublishedDisclosed and added to the National Vulnerability Database.
- Jul 23, 2026 · 12d agoAdvisory updatedThe NVD record was last revised.
- Jul 23, 2026 · 12d agoOfficial fix availableA vendor patch or mitigation now exists — see the remediation steps above.
How it’s attacked
References & advisories
- github.com/signalwire/freeswitch/relea…release notes
- github.com/signalwire/freeswitch/secur…third party advisory