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Vulnerability record · CVE-2026-49841 · published 9 June 2026

CVE-2026-49841: Freeswitch heap-based buffer overflow vulnerability

Freeswitch · Freeswitch

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.

9.8 CVSS 3.1 Critical EPSS 0.61% · top 53.2% CWE-122 · Heap-based buffer overflowCWE-131 · CWE-131
9.8CVSS 3.1 base score
0.61%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References
23 Jul 2026Last modified by NVD

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.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2019-19492Freeswitch hard-coded credentials vulnerabilityFreeSWITCH 1.6.10 through 1.10.1 has a default password in event_socket.conf.xml.EPSS 29%9.1CVE-2026-49840Freeswitch improper input validation vulnerabilityFreeSWITCH is a Software Defined Telecom Stack enabling the digital transformation from proprietary telecom switches to a software implementation tha…EPSS 0.49%7.5CVE-2026-49842Freeswitch uncontrolled resource consumption vulnerabilityFreeSWITCH is a Software Defined Telecom Stack enabling the digital transformation from proprietary telecom switches to a software implementation tha…EPSS 0.58%7.5CVE-2026-49847Freeswitch vulnerabilityFreeSWITCH is a Software Defined Telecom Stack enabling the digital transformation from proprietary telecom switches to a software implementation tha…EPSS 0.53%7.5CVE-2026-49475Freeswitch improper input validation vulnerabilityFreeSWITCH is a Software Defined Telecom Stack enabling the digital transformation from proprietary telecom switches to a software implementation tha…EPSS 0.49%7.5CVE-2026-45771Freeswitch vulnerabilityFreeSWITCH is a Software Defined Telecom Stack enabling the digital transformation from proprietary telecom switches to a software implementation tha…EPSS 0.49%7.5CVE-2023-40018Freeswitch out-of-bounds write vulnerabilityFreeSWITCH is a Software Defined Telecom Stack enabling the digital transformation from proprietary telecom switches to a software implementation tha…EPSS 0.99%7.5CVE-2021-41158Freeswitch information exposure vulnerabilityFreeSWITCH is a Software Defined Telecom Stack enabling the digital transformation from proprietary telecom switches to a software implementation tha…EPSS 0.83%

Source: NIST National Vulnerability Database (record CVE-2026-49841), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.