CVE-2026-116789 · Runtime
NO FIX YET · SEE WHAT TO DO
FreeSWITCH before 1.11.2 does not compare a peer's DTLS certificate against the SDP fingerprint when it acts as the DTLS server. An attacker able to reach the negotiated media port can take over the SRTP keys, decrypt call audio and video, inject media, and displace the real endpoint.
first public Oct 28, 2026 · 1 source
Check it with your coding agent
It checks your repository and tells you if you’re affected, with the fix.
Systems running FreeSWITCH before 1.11.2 that handle WebRTC or SIP calls using DTLS-SRTP media, where the remote peer can choose the DTLS active role. Exposure is lower on ICE-enabled legs, because an attacker also needs the connectivity-check credentials from SDP, which usually means signaling visibility or a position on the media path. Deployments that do not use DTLS-SRTP legs, or that already run 1.11.2 with the fingerprint setting, can skip it.
Not affected if fingerprint-verify-enabled, no-dtls-srtp, version-1.11.2-or-later
Who cares freeswitch, self-hosted, sip, voip, webrtc
fs_cli -x version and compare it against the fixed release.rtp_dtls_client_cert_verify_mode is set to fingerprint in the dialplan or profile settings.1.11.2 or later, and set rtp_dtls_client_cert_verify_mode=fingerprint as the source requires.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 1.11.2, dtls_state_setup() compared a peer certificate with the SDP a=fingerprint only when FreeSWITCH was the DTLS client, not when it held the DTLS server role. An unauthenticated peer able to reach the negotiated media port could complete the DTLS-SRTP handshake with an unrelated certificate, obtain the leg's SRTP keys, decrypt and inject media, and displace the legitimate endpoint; on ICE-enabled legs the peer also needs the connectivity-check credentials from SDP, which generally requires signaling visibility or a position on its path. WebRTC and SIP DTLS-SRTP legs are affected whenever the peer selects the active role, while FreeSWITCH client-role handshakes already perform fingerprint validation. Version 1.11.2 introduces the remediation, which requires rtp_dtls_client_cert_verify_mode=fingerprint.
Are you affected?
Tell InfraStack what you run. It checks this one, and every next one, against your stack.
Ask from here. InfraStack checks the affected versions against your stack and answers in your inbox.
InfraStack checks the affected versions against your stack and answers in Slack, with the evidence and the fix.
NVD data is provided by NIST and is public domain. Posts quoted belong to their authors.