Bug 2567933 (CVE-2026-116574)

Summary: CVE-2026-116574 freeswitch: freeswitch: Denial of Service (DoS) via out-of-bounds write during XML serialization
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerability-draftAssignee: Product Security DevOps Team <prodsec-dev>
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Priority: medium    
Version: unspecifiedKeywords: Security
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OS: Linux   
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A flaw was found in FreeSWITCH. When serializing user-supplied text into XML format, insufficient buffer allocation causes a single-byte out-of-bounds write beyond allocated heap memory. A remote attacker can exploit this issue by supplying specially crafted input to reachable interfaces, causing the application to abort and resulting in a Denial of Service (DoS).
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Description OSIDB Bzimport 2026-11-05 22:37:30 UTC
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, switch_xml_ampencode() reserved only ten bytes for the widest numeric character reference produced from a four-byte UTF-8 sequence, omitting space for the terminating NUL. When remote-supplied text was serialized at the exact buffer-growth boundary, the terminator wrote one byte beyond the heap allocation. Reachable surfaces include mod_xml_cdr, conference and formatted CDR XML, XML Event Socket output, and XML API output that serializes caller-controlled values. The fixed zero-byte write can abort the process or truncate an adjacent object, while remote code execution has not been demonstrated. This issue is fixed in version 1.11.2.