{"id":"CVE-2026-116787","kind":"vulnerability","aliases":["CVE-2026-116787"],"related":[],"title":"FreeSWITCH: unauthenticated Event Socket header crashes the telephony process","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.","summary":"A malformed Content-Length header on FreeSWITCH's Event Socket module, parsed before authentication, can overflow an allocation and make the process abort. Any host allowed by the inbound ACL can stop the service with one packet, dropping all active calls until restart.","severity":"high","cvss":7.5,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["freeswitch","runtime","self-hosted","telephony"],"not_affected_if":["default-config","fixed-version","no-event-socket"],"how_to_check":"- Check the FreeSWITCH version with `fs_cli -x version` or `freeswitch -version`\n- Check whether mod_event_socket is loaded and what `apply-inbound-acl` allows in `event_socket.conf.xml`\n- Check whether outbound socket dialplan connects to application servers you do not control","fix":"- FreeSWITCH: move to `1.11.2` or later","status":"open","published_at":"2026-11-05T20:17:46+00:00","first_seen_at":"2026-11-05T20:40:46+00:00","triaged_at":"2026-11-05T20:43:02+00:00","updated_at":"2026-11-05T20:43:02+00:00","category":"runtime","confidence":0.8,"triage":{"at":"2026-11-05T20:43:02Z","model":"claude-haiku-5-5","output":{"fix":"- FreeSWITCH: move to `1.11.2` or later","reach":"network","title":"FreeSWITCH: unauthenticated Event Socket header crashes the telephony process","impact":"medium","summary":"A malformed Content-Length header on FreeSWITCH's Event Socket module, parsed before authentication, can overflow an allocation and make the process abort. Any host allowed by the inbound ACL can stop the service with one packet, dropping all active calls until restart.","audience":"businesses","category":"runtime","nicknames":[],"who_cares":["freeswitch","telephony","self-hosted"],"confidence":0.8,"fix_status":"available","needs_auth":"no","worst_case":"FreeSWITCH process terminates, dropping all active calls","analyst_note":"","how_to_check":"- Check the FreeSWITCH version with `fs_cli -x version` or `freeswitch -version`\n- Check whether mod_event_socket is loaded and what `apply-inbound-acl` allows in `event_socket.conf.xml`\n- Check whether outbound socket dialplan connects to application servers you do not control","plain_action":"","needs_analyst":false,"not_affected_if":["default-config","fixed-version","no-event-socket"],"who_is_affected":"Systems running FreeSWITCH older than 1.11.2 with mod_event_socket loaded. The default loopback ACL limits exposure to local clients, so a standard install is at risk mainly where the ACL admits other hosts or where FreeSWITCH connects out to an application server that could be hostile. Installations that use only the loopback ACL with no outbound socket dialplan are lower risk.","user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"unknown"},"cost_usd":0.000748,"input_tokens":4458,"output_tokens":604,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-116787':12A,15A '-2026':11A,14A '1.11.2':93C,207C 'abort':45B,134C 'acl':52B,155C,166C 'activ':62B,194C 'admit':150C 'affect':180C 'alloc':40B,107C,128C 'allow':48B 'also':179C 'appli':153C 'applic':187C 'apply-inbound-acl':152C 'authent':36B 'bodi':114C 'calcul':124C 'call':63B,195C 'client':172C 'commod':89C 'connect':183C 'content':25B,101C 'content-length':24B,100C 'could':120C 'crash':6A 'cve':10A,13A 'default':164C 'defin':70C 'dialplan':176C 'digit':75C 'direct':104C 'drop':60B,192C 'enabl':73C 'event':3A,31B,95C,111C,144C 'everi':193C 'extrem':117C 'failur':129C 'first':161C 'fix':204C 'forc':126C 'freeswitch':1A,16B,29B,66C,136C,182C 'hardwar':90C 'header':5A,27B,139C 'helper':132C 'host':20B,47B,149C 'hostil':186C 'implement':84C 'inbound':51B,154C 'instal':169C 'issu':202C 'larg':118C 'length':26B,102C 'limit':167C 'local':171C 'loopback':165C 'make':42B 'malform':23B 'messag':113C 'mod':94C 'modul':33B 'negat':115C 'one':58B 'ordinari':168C 'outbound':174C 'overflow':38B,121C 'packet':59B,162C 'pars':34B,141C 'password':146C 'path':177C 'prior':91C 'process':9A,44B,137C,190C 'proprietari':78C 'restart':65B,200C 'run':86C 'runtim':17B 'self':19B 'self-host':18B 'server':188C 'servic':56B,198C 'size':108C 'socket':4A,32B,96C,112C,145C,175C 'softwar':69C,83C 'stack':72C 'stop':54B 'switch':80C 'telecom':71C,79C 'telephoni':8A,21B 'termin':123C,158C,191C 'transform':76C 'trigger':157C 'unauthent':2A,99C 'use':97C 'valu':103C,119C 'version':206C","nicknames":[],"mitigations":[],"who_affected":"Systems running FreeSWITCH older than 1.11.2 with mod_event_socket loaded. The default loopback ACL limits exposure to local clients, so a standard install is at risk mainly where the ACL admits other hosts or where FreeSWITCH connects out to an application server that could be hostile. Installations that use only the loopback ACL with no outbound socket dialplan are lower risk.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["freeswitch","high","runtime","selfhosted","telephony"],"campaign_type":null,"first_public_at":"2026-10-28T16:56:16+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cvss_by":"security-advisories@github.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-116787","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-116787","severity":null,"published_at":"2026-11-05T20:17:46+00:00","modified_at":"2026-11-05T20:17:46+00:00","first_seen_at":"2026-11-05T20:40:46+00:00","fetched_at":"2026-11-05T20:40:46+00:00","note":null}],"documents":[{"id":79882,"url":"https://github.com/signalwire/freeswitch/commit/a097e124213c164845dcaaa8feed2e70bc1e7191","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":79884,"url":"https://github.com/signalwire/freeswitch/security/advisories/GHSA-j27c-m99r-8pc3","title":"Vendor advisory: github.com","kind":"vendor","source":"nvd","publisher":"vendor","text":null,"published_at":"2026-10-28T16:56:16+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"}