cvedb.io
CVE-2026-49840
CRITICAL · CVSS 9.1
EPSS exploitation probability: 0%
Published 2026-06-09T17:17:47.703 · Last modified 2026-06-17T10:55:46.980

Summary

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 products

freeswitch — freeswitch

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.