CVE-2026-116567
Dashboard / Vulnerabilities / CVE-2026-116567
Summary: FreeSWITCH: Pre-authentication stack buffer overflow in mod_rtmp control-message handling
Details: 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, rtmp_handle_control() rendered an RTMP user-control message into a 200-byte stack buffer using an unbounded sprintf loop controlled by the wire message length. A body of roughly 70 bytes or more overflowed the stack before any RTMP login, because the handshake authenticates neither side. The flaw affects deployments that build and load mod_rtmp, which is disabled in the stock build and configuration but commonly exposes a listener on TCP port 1935 when enabled. One unauthenticated message can crash FreeSWITCH and end every active call; the constrained ASCII hex output has not yielded control-flow hijacking. This issue is fixed in version 1.11.2.
References: https://github.com/signalwire/freeswitch/releases/tag/v1.11.2, https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/116xxx/CVE-2026-116567.json, https://github.com/signalwire/freeswitch/security/advisories/GHSA-hj6x-9653-p796, https://nvd.nist.gov/vuln/detail/CVE-2026-116567, https://github.com/signalwire/freeswitch/commit/fc0db829b87d1a5a3043e355b4294c41851b13c6
Affected packages
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