🛡️ CVE-2026-49840
🔴 CVSS 9.1 — Critical ✅ No Known Exploit CWE-20 NVD
9.1
CVSS Score
0 Low4 Medium7 High9 Critical10

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, esl_recv_event() parses Content-Length with atol() and passes the result straight to malloc(len + 1) with no sign or magnitude check. A malicious or man-in-the-middle ESL peer can send a frame with a negative Content-Length to corrupt the heap of, or crash, any process linked against libesl, before the client has authenticated to that peer. This issue has been patched in version 1.11.1.

Details

Severity CRITICAL
CVSS Score 9.1
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
CWE CWE-20
Public Exploit ✅ No
Source NVD
Published 2026-06-09
Updated 2026-06-11
Modified 2026-06-10
Fix URL N/A

Affected Packages

Software From version Fixed in
freeswitch — 1.11.1
unknown — —

Similar Threats

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