---
id: "CVE-2026-116568"
kind: "vulnerability"
aliases: ["CVE-2026-116568"]
title: "FreeSWITCH: crafted RTMP video packet crashes the process and all calls"
severity: "high"
cvss: 7.5
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["freeswitch", "rtmp", "runtime", "self-hosted", "telephony"]
not_affected_if: ["auth-calls-true", "mod-rtmp-not-loaded", "no-rtmp-listener"]
published_at: "2026-11-05T20:17:43+00:00"
first_seen_at: "2026-11-05T20:40:44+00:00"
updated_at: "2026-11-05T20:43:09+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-116568", "first_seen_at": "2026-11-05T20:40:44+00:00"}]
exploit_sources: []
---

# FreeSWITCH: crafted RTMP video packet crashes the process and all calls

FreeSWITCH before 1.11.2 mishandles oversized H.264 NAL unit length prefixes in its mod_rtmp video path, causing an out-of-bounds read. A remote client can crash FreeSWITCH and terminate every active call, though no code execution has been demonstrated.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the FreeSWITCH version with `fs_cli -x version` and compare against `1.11.2`.
- Check whether mod_rtmp is loaded with `fs_cli -x "module_exists mod_rtmp"`.
- Check whether `auth-calls` is set to true in the RTMP configuration; if it is absent or false, no credentials are needed.

## Fix

- FreeSWITCH: upgrade to `1.11.2`.

## Timeline

- 2026-11-05T20:40:44+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-116568

## Documents

- [advisory] Vendor advisory: github.com https://github.com/signalwire/freeswitch/security/advisories/GHSA-2gp7-f34j-j4xw
- [fix] Patch: github.com https://github.com/signalwire/freeswitch/commit/72cda5bfad67d14d8dbe76b8f8bdd38c4fa5c932
- [fix] Release notes: github.com https://github.com/signalwire/freeswitch/releases/tag/v1.11.2

## From the sources

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_rtmp2rtpH264() trusted the length prefix of each inbound H.264 NAL unit without checking it against the bytes remaining in the RTMP message. An oversized declared unit underflowed the unsigned remaining-byte counter and advanced the parser beyond its receive buffer, where the next length-prefix read could crash the process. The flaw affects deployments that build and load mod_rtmp and accept video call sessions, commonly on TCP port 1935; placing the call requires a directory login where auth-calls is true, while no credentials are required where auth-calls is absent or false. A remote client can terminate FreeSWITCH and every active call, but the defect supplies no write primitive and memory disclosure has not been demonstrated. This issue is fixed in version 1.11.2.

---

_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_