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CVE-2026-116568— FreeSWITCH: Out-of-bounds read in mod_rtmp H.264 video message parsing

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栈，旨在推动从专有电信交换机向可在任何通用硬件上运行的软件实现进行数字化转型。在 1.11.2 版本之前， 函数在未将每个入站 H.264 NAL 单元的长度前缀与 RTMP 消息中剩余字节数进行校验的情况下，直接信任了该长度前缀。当声明的单元过大时，会导致无符号剩余字节计数器发生下溢，使解析器越界访问其接收缓冲区；此时，下一次读取长度前缀的操作可能引发进程崩溃。该漏洞影响部署了 模块并加载该模块、同时接受视频通话会话的 FreeSWITCH 实例（通常监听 TCP 1935

CVSS 7.5 · High

Possible ATT&CK Techniques 1 AI

T1190 · Exploit Public-Facing Application

Affected Version Matrix 1

VendorProduct Version RangeStatus
signalwire freeswitch < 1.11.2 affected
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I. Basic Information for CVE-2026-116568

Vulnerability Information
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Vulnerability Title
FreeSWITCH: Out-of-bounds read in mod_rtmp H.264 video message parsing
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, 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.
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
跨界内存读
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
signalwire freeswitch < 1.11.2 -

II. Public POCs for CVE-2026-116568

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III. Intelligence Information for CVE-2026-116568

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Other References for CVE-2026-116568 (3)

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-2026-116567 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-2026-116787 7.5 HIGH FreeSWITCH: Pre-authentication process termination in the Event Socket via an unbounded Co
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-125