{"id":"CVE-2026-106803","kind":"vulnerability","aliases":["CVE-2026-106803"],"related":[],"title":"Kamailio: crafted NOTIFY message overflows stack and crashes P-CSCF","description":"A stack-based buffer overflow exists in Kamailio v6.1.3 and v6.1.4 in the ims_registrar_pcscf module. When processing a crafted application/reginfo+xml NOTIFY message, process_contact() copies an attacker-controlled port value from the alias parameter into a fixed 5-byte stack buffer without validating its length. An unauthenticated remote attacker can trigger stack corruption and terminate the P-CSCF process, resulting in denial of service.","summary":"Kamailio's ims_registrar_pcscf module copies an attacker-supplied port from a NOTIFY message's alias parameter into a fixed 5-byte stack buffer without a length check. An unauthenticated remote attacker can corrupt the stack and terminate the P-CSCF process, causing denial of service.","severity":"high","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["ims","kamailio","runtime","sip","voip"],"not_affected_if":["module-not-loaded","other-kamailio-versions"],"how_to_check":"- Check the installed Kamailio version with `kamailio -v`; versions 6.1.3 and 6.1.4 are affected.\n- Check whether the ims_registrar_pcscf module is loaded in the Kamailio configuration.","fix":"- Patch link is listed in the sources but the fixed version is unknown.","status":"open","published_at":"2026-11-02T17:17:33+00:00","first_seen_at":"2026-11-02T17:24:12+00:00","triaged_at":"2026-11-02T17:26:28+00:00","updated_at":"2026-11-02T17:26:28+00:00","category":"runtime","confidence":0.6,"triage":{"at":"2026-11-02T17:26:28Z","model":"claude-haiku-5-5","output":{"fix":"- Patch link is listed in the sources but the fixed version is unknown.","reach":"network","title":"Kamailio: crafted NOTIFY message overflows stack and crashes P-CSCF","impact":"low","summary":"Kamailio's ims_registrar_pcscf module copies an attacker-supplied port from a NOTIFY message's alias parameter into a fixed 5-byte stack buffer without a length check. An unauthenticated remote attacker can corrupt the stack and terminate the P-CSCF process, causing denial of service.","audience":"businesses","category":"runtime","nicknames":[],"who_cares":["kamailio","voip","ims","sip"],"confidence":0.6,"fix_status":"available","needs_auth":"no","worst_case":"Remote attacker crashes the P-CSCF process, causing denial of service","analyst_note":"Confirm the fixed version and the patch commit from the github.com patch link; the sources do not name the fixed release.","how_to_check":"- Check the installed Kamailio version with `kamailio -v`; versions 6.1.3 and 6.1.4 are affected.\n- Check whether the ims_registrar_pcscf module is loaded in the Kamailio configuration.","plain_action":"","needs_analyst":true,"not_affected_if":["other-kamailio-versions","module-not-loaded"],"who_is_affected":"Deployments of Kamailio 6.1.3 or 6.1.4 that run the ims_registrar_pcscf module as a P-CSCF and accept reginfo+xml NOTIFY messages from the network are exposed. Systems on other Kamailio versions or without this module are not described as affected.","user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"high"},"cost_usd":0.000722,"input_tokens":4199,"output_tokens":604,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-106803':14A,17A '-2026':13A,16A '5':45B,114C 'alia':40B,109C 'application/reginfo':94C 'attack':32B,56B,103C,125C 'attacker-control':102C 'attacker-suppli':31B 'base':75C 'buffer':48B,76C,117C 'byte':46B,115C 'caus':68B 'check':52B 'contact':99C 'control':104C 'copi':29B,100C 'corrupt':58B,129C 'craft':2A,93C 'crash':8A 'cscf':11A,66B,135C 'cve':12A,15A 'denial':69B,139C 'exist':78C 'fix':44B,113C 'im':18B,25B,86C 'kamailio':1A,19B,23B,80C 'length':51B,121C 'messag':4A,38B,97C 'modul':28B,89C 'notifi':3A,37B,96C 'overflow':5A,77C 'p':10A,65B,134C 'p-cscf':9A,64B,133C 'paramet':41B,110C 'pcscf':27B,88C 'port':34B,105C 'process':67B,91C,98C,136C 'registrar':26B,87C 'remot':55B,124C 'result':137C 'runtim':20B 'servic':71B,141C 'sip':21B 'stack':6A,47B,60B,74C,116C,128C 'stack-bas':73C 'suppli':33B 'termin':62B,131C 'trigger':127C 'unauthent':54B,123C 'v6.1.3':81C 'v6.1.4':83C 'valid':119C 'valu':106C 'voip':22B 'without':49B,118C 'xml':95C","nicknames":[],"mitigations":[],"who_affected":"Deployments of Kamailio 6.1.3 or 6.1.4 that run the ims_registrar_pcscf module as a P-CSCF and accept reginfo+xml NOTIFY messages from the network are exposed. Systems on other Kamailio versions or without this module are not described as affected.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["high","ims","kamailio","runtime","sip","voip"],"first_public_at":"2026-11-02T17:17:33+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-106803","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-106803","severity":null,"published_at":"2026-11-02T17:17:33+00:00","modified_at":"2026-11-02T17:17:33+00:00","first_seen_at":"2026-11-02T17:24:12+00:00","fetched_at":"2026-11-02T17:24:12+00:00","note":null}],"documents":[{"id":53008,"url":"https://github.com/kamailio/kamailio/commit/21261436492f0014930e804e20586e3833bb91b9","title":"Patch: github.com","kind":"other","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Patch: github.com"}],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}