{"id":"CVE-2026-98593","kind":"vulnerability","aliases":["CVE-2026-98593"],"related":[],"title":"Linux kernel s390 debug facility: NULL pointer dereference crashes the kernel","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ns390/debug: Fix NULL pointer dereference in debug_info_copy()\n\nWhen debug_register_static() fails, it clears areas, active_pages and\nactive_entries but leaves the area bounds unchanged. Copying such an\narea, either by opening its view file or via debug_dump(), makes\ndebug_info_copy() dereference the NULL pointers.\n\nSkip the copy loop when the source has no areas.","summary":"When a static debug area fails to register on IBM s390 systems, the kernel leaves its area bounds set while clearing the pointers. Opening the debug view file or running debug_dump() then dereferences those NULL pointers and can crash the machine.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["linux-kernel","mainframe","runtime","s390"],"not_affected_if":["non-s390-hardware"],"how_to_check":null,"fix":null,"status":"open","published_at":"2026-10-18T16:17:11+00:00","first_seen_at":"2026-10-23T21:57:16+00:00","triaged_at":"2026-10-25T05:21:40+00:00","updated_at":"2026-10-25T05:21:40+00:00","category":"runtime","confidence":0.5,"triage":{"at":"2026-10-25T05:21:40Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"local","title":"Linux kernel s390 debug facility: NULL pointer dereference crashes the kernel","impact":"low","summary":"When a static debug area fails to register on IBM s390 systems, the kernel leaves its area bounds set while clearing the pointers. Opening the debug view file or running debug_dump() then dereferences those NULL pointers and can crash the machine.","category":"runtime","nicknames":[],"who_cares":["linux-kernel","s390","mainframe"],"confidence":0.5,"needs_auth":"unknown","worst_case":"local users can crash the kernel via debug views","analyst_note":"","how_to_check":"unknown","needs_analyst":false,"not_affected_if":["non-s390-hardware"],"who_is_affected":"unknown","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"unknown"},"cost_usd":0.000495,"input_tokens":3369,"output_tokens":317,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2026':13A,16A '-98593':14A,17A 'activ':93C,96C 'area':28B,40B,92C,101C,107C,135C 'bound':41B,102C 'clear':44B,91C 'copi':84C,104C,121C,128C 'crash':9A,63B 'cve':12A,15A 'debug':4A,27B,49B,54B,82C,86C,116C,119C 'derefer':8A,57B,80C,122C 'dump':55B,117C 'either':108C 'entri':97C 'facil':5A 'fail':29B,89C 'file':51B,113C 'fix':77C 'follow':71C 'ibm':33B 'info':83C,120C 'kernel':2A,11A,20B,37B,69C 'leav':38B,99C 'linux':1A,19B,68C 'linux-kernel':18B 'loop':129C 'machin':65B 'mainfram':21B 'make':118C 'null':6A,59B,78C,124C 'open':47B,110C 'page':94C 'pointer':7A,46B,60B,79C,125C 'regist':31B,87C 'resolv':75C 'run':53B 'runtim':22B 's390':3A,23B,34B 's390/debug':76C 'set':42B 'skip':126C 'sourc':132C 'static':26B,88C 'system':35B 'unchang':103C 'via':115C 'view':50B,112C 'vulner':72C","nicknames":[],"mitigations":[],"who_affected":null,"tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-18T16:17:11+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-98593","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98593","severity":null,"published_at":"2026-10-18T16:17:11+00:00","modified_at":"2026-10-19T10:19:20+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"}