{"id":"CVE-2026-98747","kind":"vulnerability","aliases":["CVE-2026-98747"],"related":[],"title":"Linux kernel serial core: NULL pointer dereference on serial port unregister","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nserial: core: fix NULL pointer dereference in serial_core_unregister_port()\n\nport->port_dev is NULL when no port device is installed: it is cleared\non teardown, and never set if registration failed before\nserial_core_port_device_add().  serial_core_unregister_port() passes it\nstraight to serial_core_get_ctrl_dev(), which dereferences it:\n\n  KASAN: null-ptr-deref in range [0x0000000000000040-0x0000000000000047]\n  RIP: serial_core_unregister_port\n  Call Trace:\n   serial8250_unregister_port\n   serial8250_remove\n   unbind_store\n\nReturn early when there is no port device, and read port->port_dev\nunder port_mutex.\n\nAlso clear port->port_dev on the serial_core_register_port() error\npath, where the port device has already been removed.","summary":"In the Linux kernel serial core, unregistering a port with no port device installed dereferences a NULL pointer and crashes the kernel. The sources describe a crash path triggered through unbinding the serial8250 driver, with no stated code execution or data exposure.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["kernel","linux","other","serial"],"not_affected_if":[],"how_to_check":null,"fix":null,"status":"open","published_at":"2026-10-18T16:17:28+00:00","first_seen_at":"2026-10-23T21:57:16+00:00","triaged_at":"2026-10-25T05:16:57+00:00","updated_at":"2026-10-25T05:16:57+00:00","category":"other","confidence":0.5,"triage":{"at":"2026-10-25T05:16:57Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"local","title":"Linux kernel serial core: NULL pointer dereference on serial port unregister","impact":"low","summary":"In the Linux kernel serial core, unregistering a port with no port device installed dereferences a NULL pointer and crashes the kernel. The sources describe a crash path triggered through unbinding the serial8250 driver, with no stated code execution or data exposure.","category":"other","nicknames":[],"who_cares":["linux","kernel","serial"],"confidence":0.5,"needs_auth":"unknown","worst_case":"Kernel crash from a NULL pointer dereference during serial port removal","analyst_note":"Check the upstream kernel stable commits and the NVD entry for affected kernel version ranges and fixed versions.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":[],"who_is_affected":"unknown","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"unknown"},"cost_usd":0.000525,"input_tokens":3507,"output_tokens":349,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2026':13A,16A '-98747':14A,17A '0x0000000000000040':137C '0x0000000000000040-0x0000000000000047':136C '0x0000000000000047':138C 'add':112C 'alreadi':187C 'also':169C 'call':144C 'clear':98C,170C 'code':59B 'core':4A,27B,75C,82C,109C,114C,122C,141C,177C 'crash':41B,48B 'ctrl':124C 'cve':12A,15A 'data':62B 'deref':133C 'derefer':7A,36B,79C,127C 'describ':46B 'dev':87C,125C,165C,173C 'devic':34B,93C,111C,160C,185C 'driver':55B 'earli':154C 'error':180C 'execut':60B 'exposur':63B 'fail':106C 'fix':76C 'follow':69C 'get':123C 'instal':35B,95C 'kasan':129C 'kernel':2A,18B,25B,43B,67C 'linux':1A,19B,24B,66C 'mutex':168C 'never':102C 'null':5A,38B,77C,89C,131C 'null-ptr-deref':130C 'pass':117C 'path':49B,181C 'pointer':6A,39B,78C 'port':10A,30B,33B,84C,85C,86C,92C,110C,116C,143C,148C,159C,163C,164C,167C,171C,172C,179C,184C 'ptr':132C 'rang':135C 'read':162C 'regist':178C 'registr':105C 'remov':150C,189C 'resolv':73C 'return':153C 'rip':139C 'serial':3A,9A,21B,26B,74C,81C,108C,113C,121C,140C,176C 'serial8250':54B,146C,149C 'set':103C 'sourc':45B 'state':58B 'store':152C 'straight':119C 'teardown':100C 'trace':145C 'trigger':50B 'unbind':52B,151C 'unregist':11A,28B,83C,115C,142C,147C 'vulner':70C","nicknames":[],"mitigations":[],"who_affected":null,"tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-18T16:17:28+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-98747","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98747","severity":null,"published_at":"2026-10-18T16:17:28+00:00","modified_at":"2026-10-19T10:19:38+00:00","first_seen_at":"2026-10-23T21:57:16+00:00","fetched_at":"2026-10-23T22:28:56+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}