{"id":"CVE-2026-116574","title":"FreeSWITCH: Off-by-one heap write in core XML serialization of four-byte UTF-8 sequences","summary":"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 …","severity":"medium","cvss":5.9,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H","cvssSource":"cna","cwe":["CWE-193","CWE-787"],"vendor":"signalwire","product":"freeswitch","affected":["freeswitch < 1.11.2"],"published":"2026-11-05","updated":"2026-11-05","sourceUpdated":"2026-11-05T19:00:26.440Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-116574","references":[{"url":"https://github.com/signalwire/freeswitch/security/advisories/GHSA-r6vh-qmwm-h3cc","label":"https://github.com/signalwire/freeswitch/security/advisories/GHSA-r6vh-qmwm-h3cc"},{"url":"https://github.com/signalwire/freeswitch/commit/28fcfd26246c112fa4b9e698433d09e4836ca1b5","label":"https://github.com/signalwire/freeswitch/commit/28fcfd26246c112fa4b9e698433d09e4836ca1b5"},{"url":"https://github.com/signalwire/freeswitch/releases/tag/v1.11.2","label":"https://github.com/signalwire/freeswitch/releases/tag/v1.11.2"}],"tags":["cve.org"],"ingestedAt":"2026-11-05T22:38:31.489Z","slug":"CVE-2026-116574","body":"## Overview\n\nFreeSWITCH 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.\n\n## Affected\n\n- `freeswitch < 1.11.2`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":32,"depthScoreParts":{"impact":32.5,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}