{"id":"CVE-2026-98495","kind":"vulnerability","aliases":["CVE-2026-98495"],"related":[],"title":"Linux kernel: ARP ioctl reads past a stack buffer during device lookup","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: arp: terminate device name before lookup\n\nThe ARP ioctl copies a user-provided struct arpreq into a stack object. Its\narp_dev field may contain IFNAMSIZ bytes without a NUL terminator.\n\nSuch input is passed to dev_get_by_name_rcu() or __dev_get_by_name(), where\nstrcmp() can read past the end of the stack object when a matching\nalternative interface name exists.\n\nTerminate the field before the lookup to prevent the out-of-bounds read.","summary":"The Linux kernel's ARP ioctl copies a user-supplied device name that may lack a NUL terminator, and the name lookup can then read past the end of a stack object when a matching alternative interface name exists. The sources describe an out-of-bounds read, not a write, and do not state a severity or the resulting impact beyond that.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["infrastructure","kernel","linux","networking"],"not_affected_if":[],"how_to_check":"- unknown","fix":"- unknown","status":"open","published_at":"2026-10-18T16:17:00+00:00","first_seen_at":"2026-10-23T21:57:15+00:00","triaged_at":"2026-10-25T05:25:37+00:00","updated_at":"2026-10-25T05:25:37+00:00","category":"infrastructure","confidence":0.4,"triage":{"at":"2026-10-25T05:25:37Z","model":"claude-haiku-5-5","output":{"fix":"- unknown","reach":"local","title":"Linux kernel: ARP ioctl reads past a stack buffer during device lookup","impact":"low","summary":"The Linux kernel's ARP ioctl copies a user-supplied device name that may lack a NUL terminator, and the name lookup can then read past the end of a stack object when a matching alternative interface name exists. The sources describe an out-of-bounds read, not a write, and do not state a severity or the resulting impact beyond that.","category":"infrastructure","nicknames":[],"who_cares":["linux","kernel","networking"],"confidence":0.4,"needs_auth":"unknown","worst_case":"Kernel reads past a stack buffer; information leak or crash possible","analyst_note":"Find the fixed kernel versions and stable commit in the NVD entry (https://nvd.nist.gov/vuln/detail/CVE-2026-98495) and the linked kernel.org stable patches.","how_to_check":"- unknown","needs_analyst":true,"not_affected_if":[],"who_is_affected":"Systems running a Linux kernel with the affected net/arp code, where a local process can issue ARP ioctls. The sources do not list affected kernel versions or say which configurations are exposed.","user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"low"},"cost_usd":0.00057,"input_tokens":3397,"output_tokens":461,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2026':14A,17A '-98495':15A,18A 'altern':59B,158C 'arp':3A,27B,97C,104C,118C 'arpreq':112C 'beyond':85B 'bound':70B,174C 'buffer':9A 'byte':124C 'contain':122C 'copi':29B,106C 'cve':13A,16A 'describ':65B 'dev':119C,134C,140C 'devic':11A,34B,99C 'end':51B,150C 'exist':62B,161C 'field':120C,164C 'follow':91C 'get':135C,141C 'ifnamsiz':123C 'impact':84B 'infrastructur':19B 'input':130C 'interfac':60B,159C 'ioctl':4A,28B,105C 'kernel':2A,20B,25B,89C 'lack':38B 'linux':1A,21B,24B,88C 'lookup':12A,45B,102C,167C 'match':58B,157C 'may':37B,121C 'name':35B,44B,61B,100C,137C,143C,160C 'net':96C 'network':22B 'nul':40B,127C 'object':55B,116C,154C 'out-of-bound':67B,171C 'pass':132C 'past':6A,49B,148C 'prevent':169C 'provid':110C 'rcu':138C 'read':5A,48B,71B,147C,175C 'resolv':95C 'result':83B 'sever':80B 'sourc':64B 'stack':8A,54B,115C,153C 'state':78B 'strcmp':145C 'struct':111C 'suppli':33B 'termin':41B,98C,128C,162C 'user':32B,109C 'user-provid':108C 'user-suppli':31B 'vulner':92C 'without':125C 'write':74B","nicknames":[],"mitigations":[],"who_affected":"Systems running a Linux kernel with the affected net/arp code, where a local process can issue ARP ioctls. The sources do not list affected kernel versions or say which configurations are exposed.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-18T16:17:00+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-98495","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98495","severity":null,"published_at":"2026-10-18T16:17:00+00:00","modified_at":"2026-10-19T10:19:01+00:00","first_seen_at":"2026-10-23T21:57:15+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"}