CVE-2026-115928

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, switch core media add crypto() passed the encoded key and salt length from an inbound SDP a=crypto attribute to switch b64 decode() as the destination capacity. A zero-length key and salt made that capacity underflow, allowing the decoded attribute to overflow a fixed stack buffer with sender-chosen bytes before the call was answered. On the shipped external profile, an unauthenticated caller can reach the SDES-SRTP parser, while profiles that challenge inbound calls remain affected for senders who can authenticate; setting rtp secure media inbound to false removes the path, and WebRTC DTLS-SRTP legs are unaffected. The overflow corrupts memory and can crash the FreeSWITCH process, dropping every active call, although remote code execution has not been demonstrated. This issue is fixed in version 1.11.2.