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CVE-2026-116787— FreeSWITCH: Pre-authentication process termination in the Event Socket via an unbounded Content-Length

Quick assessment

Affected

signalwire freeswitch

Exploitation

No confirmed in-the-wild exploitation; assess based on exposure

Recommended action

Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

FreeSWITCH 是一个软件定义电信堆栈，旨在推动电信交换机从专有硬件向可运行在任何通用硬件上的软件实现进行数字化转型。在 1.11.2 版本之前，mod_event_socket 模块将未经验证的 Content-Length 值直接用作事件套接字（Event Socket）消息体的分配大小。负值或极大的值可能导致终结符（terminator）计算溢出，或通过辅助函数触发分配失败，进而导致 FreeSWITCH 进程中止。由于该头部在事件套接字密码验证之前就被解析，因此任何被 apply-inbound-ac

CVSS 7.5 · High Updated Nov 06, 2026

Possible ATT&CK Techniques 2 AI

T1499 · Endpoint Denial of Service T1190 · Exploit Public-Facing Application

Affected Version Matrix 1

Vendor	Product	Version Range	Status
signalwire	freeswitch	`< 1.11.2`	affected

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Vulnerability Information

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Vulnerability Title

FreeSWITCH: Pre-authentication process termination in the Event Socket via an unbounded Content-Length

Source: CVE Program / CVE List V5

Vulnerability 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, mod_event_socket used an unauthenticated Content-Length value directly as the allocation size for an Event Socket message body. Negative or extremely large values could overflow the terminator calculation or force an allocation failure through a helper that aborts the FreeSWITCH process. The header is parsed before the Event Socket password, so any host admitted by apply-inbound-acl can trigger termination with its first packet; the default loopback ACL limits ordinary installations to local clients. The outbound socket dialplan path is also affected when FreeSWITCH connects to a hostile application server, and process termination drops every active call until the service is restarted. This issue is fixed in version 1.11.2.

Source: CVE Program / CVE List V5

CVSS Information

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Source: CVE Program / CVE List V5

Vulnerability Type

整数溢出或超界折返

Source: CVE Program / CVE List V5

Affected Products

Vendor	Product	Affected Versions	CPE	Subscribe
signalwire	freeswitch	< 1.11.2	-

II. Public POCs for CVE-2026-116787

#	POC Description	Source Link	Shenlong Link

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III. Intelligence Information for CVE-2026-116787

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Other References for CVE-2026-116787 (3)

https://github.com/signalwire/freeswitch/releases/tag/v1.11.2 x_refsource_MISC
https://github.com/signalwire/freeswitch/security/advisories/GHSA-j27c-m99r-8pc3 x_refsource_CONFIRM
https://github.com/signalwire/freeswitch/commit/a097e124213c164845dcaaa8feed2e70bc1e7191 x_refsource_MISC

https://www.cve.org/CVERecord?id=CVE-2026-116787

Same Patch Batch · signalwire · 2026-11-05 · 21 CVEs total

CVE-2026-116779	9.8 CRITICAL	FreeSWITCH: Inbound SIP MESSAGE can select the api chat proto and run FreeSWITCH API comma
CVE-2026-116785	9.1 CRITICAL	FreeSWITCH: Pre-authentication heap out-of-bounds write in mod_xml_rpc WebSocket frame len
CVE-2026-116790	9.1 CRITICAL	FreeSWITCH: Inbound ICE connectivity checks are accepted without verifying STUN MESSAGE-IN
CVE-2026-116786	8.8 HIGH	FreeSWITCH: Channel-variable injection via SIP REFER leads to command execution in mod_sof
CVE-2026-116783	8.2 HIGH	FreeSWITCH mod_spandsp: out-of-bounds write parsing UDPTL error-recovery data
CVE-2026-116788	8.2 HIGH	FreeSWITCH: Pre-authentication heap buffer overflow in core XML empty-entity decoding
CVE-2026-116782	7.5 HIGH	FreeSWITCH: Pre-authentication invalid pointer dereference in mod_rtmp connect command han
CVE-2026-116569	7.5 HIGH	FreeSWITCH: Pre-authentication out-of-bounds write in MSRP message body parsing
CVE-2026-116568	7.5 HIGH	FreeSWITCH: Out-of-bounds read in mod_rtmp H.264 video message parsing
CVE-2026-116567	7.5 HIGH	FreeSWITCH: Pre-authentication stack buffer overflow in mod_rtmp control-message handling
CVE-2026-116570	7.5 HIGH	FreeSWITCH: Pre-authentication stack buffer overflow in mod_xml_rpc HTTP directory authent
CVE-2026-115928	7.5 HIGH	FreeSWITCH: Stack buffer overflow parsing the SDP a=crypto key material on inbound calls
CVE-2026-116784	7.5 HIGH	FreeSWITCH: Out-of-bounds read in RTCP NACK feedback parsing
CVE-2026-116789	7.4 HIGH	FreeSWITCH: DTLS-SRTP peer certificate is not bound to the SDP fingerprint when FreeSWITCH
CVE-2026-116572	6.5 MEDIUM	FreeSWITCH mod_sofia: stack buffer overflow from an over-long SIP Contact display-name
CVE-2026-116573	6.5 MEDIUM	FreeSWITCH mod_sofia: stack buffer overflow from an over-long SIP To-header user
CVE-2026-116571	5.9 MEDIUM	FreeSWITCH: Stack buffer overflow in mod_rtmp AVC sequence-header construction
CVE-2026-116574	5.9 MEDIUM	FreeSWITCH: Off-by-one heap write in core XML serialization of four-byte UTF-8 sequences
CVE-2026-116781	5.3 MEDIUM	FreeSWITCH: Pre-authentication out-of-bounds writes in mod_xml_rpc WebSocket frame parsing
CVE-2026-116780	2.7 LOW	FreeSWITCH: Heap out-of-bounds read in FreeSWITCH core variable expansion via `${variable:

IV. Related Vulnerabilities

Same product: freeswitch

Same vendor: signalwire

Same weakness: CWE-190