{"id":"CVE-2026-116785","kind":"vulnerability","aliases":["CVE-2026-116785"],"related":[],"title":"FreeSWITCH: WebSocket frame length overflow lets unauthenticated clients corrupt memory","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, ws_read_frame() decoded a WebSocket frame's 64-bit extended payload length with a 32-bit byte swap and narrowed the result into a signed length. A value whose surviving low word became negative bypassed the signed size check and was reinterpreted as an enormous unsigned count, causing client bytes to overwrite memory beyond the 64 KiB receive buffer. Any client completing a /socket WebSocket upgrade on an enabled mod_xml_rpc endpoint reached the parser before HTTP authentication; both the module and WebSocket endpoint are disabled by default. The heap overwrite can corrupt connection pointers and crash FreeSWITCH, ending every concurrent session, although remote code execution has not been demonstrated. This issue is fixed in version 1.11.2.","summary":"FreeSWITCH before 1.11.2 mishandles 64-bit WebSocket payload lengths in ws_read_frame(), causing a heap overwrite past a 64 KiB buffer. An unauthenticated remote client can crash FreeSWITCH and end all concurrent sessions; remote code execution has not been demonstrated.","severity":"critical","cvss":9.1,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["freeswitch","runtime","telecom","voip","websocket"],"not_affected_if":["default-config","fixed-1.11.2-or-later","mod-xml-rpc-disabled","websocket-disabled"],"how_to_check":"- Check the FreeSWITCH version with `fs_cli -x version` and confirm whether it is below `1.11.2`.\n- Check whether mod_xml_rpc is loaded and its WebSocket `/socket` endpoint is enabled in the mod_xml_rpc configuration.\n- Confirm whether the service is reachable from untrusted networks.","fix":"- FreeSWITCH: move to `1.11.2` or later.","status":"open","published_at":"2026-11-05T20:17:45+00:00","first_seen_at":"2026-11-05T20:40:45+00:00","triaged_at":"2026-11-05T20:42:50+00:00","updated_at":"2026-11-05T20:42:50+00:00","category":"runtime","confidence":0.8,"triage":{"at":"2026-11-05T20:42:50Z","model":"claude-haiku-5-5","output":{"fix":"- FreeSWITCH: move to `1.11.2` or later.","reach":"network","title":"FreeSWITCH: WebSocket frame length overflow lets unauthenticated clients corrupt memory","impact":"high","summary":"FreeSWITCH before 1.11.2 mishandles 64-bit WebSocket payload lengths in ws_read_frame(), causing a heap overwrite past a 64 KiB buffer. An unauthenticated remote client can crash FreeSWITCH and end all concurrent sessions; remote code execution has not been demonstrated.","audience":"businesses","category":"runtime","nicknames":[],"who_cares":["freeswitch","telecom","voip","websocket"],"confidence":0.8,"fix_status":"available","needs_auth":"no","worst_case":"Remote clients crash FreeSWITCH and corrupt connection memory; code execution not shown","analyst_note":"","how_to_check":"- Check the FreeSWITCH version with `fs_cli -x version` and confirm whether it is below `1.11.2`.\n- Check whether mod_xml_rpc is loaded and its WebSocket `/socket` endpoint is enabled in the mod_xml_rpc configuration.\n- Confirm whether the service is reachable from untrusted networks.","plain_action":"","needs_analyst":false,"not_affected_if":["default-config","mod-xml-rpc-disabled","websocket-disabled","fixed-1.11.2-or-later"],"who_is_affected":"Only deployments that run a FreeSWITCH version before 1.11.2 with mod_xml_rpc loaded and its WebSocket /socket endpoint enabled are exposed; both are disabled by default. The parser runs before HTTP authentication, so any client that can reach the endpoint can trigger it, and the main impact is a crash that drops all sessions.","user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"critical"},"cost_usd":0.000787,"input_tokens":4504,"output_tokens":674,"severity_before":"critical"},"analyst_status":null,"analyst_note":null,"search":"'-116785':13A,16A '-2026':12A,15A '/socket':155C '1.11.2':24B,90C,209C '32':106C '64':26B,41B,99C,147C 'although':195C 'authent':170C 'becam':124C 'beyond':145C 'bit':27B,100C,107C 'buffer':43B,150C 'bypass':126C 'byte':108C,141C 'caus':35B,139C 'check':130C 'client':8A,47B,140C,152C 'code':57B,197C 'commod':86C 'complet':153C 'concurr':54B,193C 'connect':186C 'corrupt':9A,185C 'count':138C 'crash':49B,189C 'cve':11A,14A 'decod':94C 'default':180C 'defin':67C 'demonstr':62B,202C 'digit':72C 'disabl':178C 'enabl':70C,160C 'end':52B,191C 'endpoint':164C,176C 'enorm':136C 'everi':192C 'execut':58B,198C 'extend':101C 'fix':206C 'frame':3A,34B,93C,97C 'freeswitch':1A,17B,22B,50B,63C,190C 'hardwar':87C 'heap':37B,182C 'http':169C 'implement':81C 'issu':204C 'kib':42B,148C 'length':4A,30B,103C,117C 'let':6A 'low':122C 'memori':10A,144C 'mishandl':25B 'mod':161C 'modul':173C 'narrow':111C 'negat':125C 'overflow':5A 'overwrit':38B,143C,183C 'parser':167C 'past':39B 'payload':29B,102C 'pointer':187C 'prior':88C 'proprietari':75C 'reach':165C 'read':33B,92C 'receiv':149C 'reinterpret':133C 'remot':46B,56B,196C 'result':113C 'rpc':163C 'run':83C 'runtim':18B 'session':55B,194C 'sign':116C,128C 'size':129C 'softwar':66C,80C 'stack':69C 'surviv':121C 'swap':109C 'switch':77C 'telecom':19B,68C,76C 'transform':73C 'unauthent':7A,45B 'unsign':137C 'upgrad':157C 'valu':119C 'version':208C 'voip':20B 'websocket':2A,21B,28B,96C,156C,175C 'whose':120C 'word':123C 'ws':32B,91C 'xml':162C","nicknames":[],"mitigations":[],"who_affected":"Only deployments that run a FreeSWITCH version before 1.11.2 with mod_xml_rpc loaded and its WebSocket /socket endpoint enabled are exposed; both are disabled by default. The parser runs before HTTP authentication, so any client that can reach the endpoint can trigger it, and the main impact is a crash that drops all sessions.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["critical","freeswitch","runtime","telecom","voip","websocket"],"campaign_type":null,"first_public_at":"2026-10-28T16:50:33+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H","cvss_by":"security-advisories@github.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-116785","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-116785","severity":null,"published_at":"2026-11-05T20:17:45+00:00","modified_at":"2026-11-05T20:17:45+00:00","first_seen_at":"2026-11-05T20:40:45+00:00","fetched_at":"2026-11-05T20:40:45+00:00","note":null}],"documents":[{"id":79876,"url":"https://github.com/signalwire/freeswitch/commit/d557ca6d29e6da4f10824dc158100906a592b91a","title":"Patch: github.com","kind":"other","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Patch: github.com"},{"id":79176,"url":"https://github.com/signalwire/freeswitch/releases/tag/v1.11.2","title":"Release notes: github.com","kind":"release","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Release notes: github.com"},{"id":79878,"url":"https://github.com/signalwire/freeswitch/security/advisories/GHSA-jj89-q47c-gh94","title":"Vendor advisory: github.com","kind":"vendor","source":"nvd","publisher":"vendor","text":null,"published_at":"2026-10-28T16:50:33+00:00","relation":"advisory","confidence":null,"note":"Vendor advisory: github.com"}],"exploit_sources":[],"notice":"Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai"}