CVE-2026-49840

The record

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.

Affected packages

Related vulnerabilities

• CVE-2026-113786 pypdf is a free and open-source pure-python PDF library. CWE-20
• CVE-2026-112081 A vulnerability was determined in hankcs HanLP up to 2.1.0-beta.64. CWE-20
• CVE-2026-111869 A vulnerability was identified in makeplane plane up to 1.4.2. CWE-20
• CVE-2026-100347 kin-openapi is a Go project for handling OpenAPI files. CWE-20
• CVE-2026-99999 In the Linux kernel, the following vulnerability has been resolved: ipv4: validate… CWE-20
• CVE-2026-107726 Hazelcast is a unified real-time data platform combining stream processing with a fast… CWE-20
• CVE-2026-105757 vLLM is an inference and serving engine for large language models. CWE-20
• CVE-2026-105756 vLLM is an inference and serving engine for large language models. CWE-20