{"id":"CVE-2026-63540","kind":"vulnerability","aliases":["CVE-2026-63540"],"related":[],"title":"Hyperscan: heap buffer overflow lets a local user crash the system","description":"Heap-based buffer overflow for some Hyperscan before version v5.4.2.1 within Ring 3: User Applications may allow a denial of service. Unprivileged software adversary with an unauthenticated user combined with a low complexity attack may enable denial of service. This result may potentially occur via local access when attack requirements are not present without special internal knowledge and requires passive user interaction. The potential vulnerability may impact the confidentiality (none), integrity (low) and availability (high) of the vulnerable system, resulting in subsequent system confidentiality (none), integrity (none) and availability (none) impacts.","summary":"Hyperscan, Intel's regular-expression matching library, has a heap-based buffer overflow before version v5.4.2.1 that an unprivileged local user can trigger. An attacker can cause a denial of service, and the description also notes possible integrity impact.","severity":"medium","cvss":6.9,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["c","hyperscan","package","regex"],"not_affected_if":["hyperscan-not-installed","version-at-or-above-5.4.2.1"],"how_to_check":"- Check the installed Hyperscan version against `v5.4.2.1`","fix":"- Hyperscan: move to `v5.4.2.1` or later","status":"open","published_at":"2026-11-10T18:17:45+00:00","first_seen_at":"2026-11-10T18:23:01+00:00","triaged_at":"2026-11-10T18:24:34+00:00","updated_at":"2026-11-10T18:24:34+00:00","category":"package","confidence":0.6,"triage":{"at":"2026-11-10T18:24:34Z","model":"claude-haiku-5-5","output":{"fix":"- Hyperscan: move to `v5.4.2.1` or later","reach":"local","title":"Hyperscan: heap buffer overflow lets a local user crash the system","impact":"medium","summary":"Hyperscan, Intel's regular-expression matching library, has a heap-based buffer overflow before version v5.4.2.1 that an unprivileged local user can trigger. An attacker can cause a denial of service, and the description also notes possible integrity impact.","audience":"developers","category":"package","nicknames":[],"who_cares":["hyperscan","c","regex"],"confidence":0.6,"fix_status":"available","needs_auth":"yes","worst_case":"local user crashes the service via heap overflow","analyst_note":"Confirm the affected Hyperscan version range and whether exploitation needs a specific input; the source describes a generic CVSS 4.0 vector with no product ranges.","how_to_check":"- Check the installed Hyperscan version against `v5.4.2.1`\n- unknown","plain_action":"","product_name":"","needs_analyst":true,"not_affected_if":["hyperscan-not-installed","version-at-or-above-5.4.2.1"],"who_is_affected":"Applications running Hyperscan in Ring 3 user space that pass data through its matching engine are the ones exposed. Systems that do not use Hyperscan are not affected. The sources do not say which configurations or inputs are needed beyond local access.","user_interaction":"yes","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"unknown"},"cost_usd":0.000729,"input_tokens":4661,"output_tokens":525,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-2026':13A,16A '-63540':14A,17A '3':76C 'access':110C 'adversari':87C 'allow':80C 'also':58B 'applic':78C 'attack':48B,97C,112C 'avail':137C,152C 'base':34B,65C 'buffer':3A,35B,66C 'c':18B 'caus':50B 'combin':92C 'complex':96C 'confidenti':132C,147C 'crash':9A 'cve':12A,15A 'denial':52B,82C,100C 'descript':57B 'enabl':99C 'express':27B 'heap':2A,33B,64C 'heap-bas':32B,63C 'high':138C 'hyperscan':1A,19B,22B,70C 'impact':62B,130C,154C 'integr':61B,134C,149C 'intel':23B 'interact':125C 'intern':119C 'knowledg':120C 'let':5A 'librari':29B 'local':7A,43B,109C 'low':95C,135C 'match':28B 'may':79C,98C,105C,129C 'none':133C,148C,150C,153C 'note':59B 'occur':107C 'overflow':4A,36B,67C 'packag':20B 'passiv':123C 'possibl':60B 'potenti':106C,127C 'present':116C 'regex':21B 'regular':26B 'regular-express':25B 'requir':113C,122C 'result':104C,143C 'ring':75C 'servic':54B,84C,102C 'softwar':86C 'special':118C 'subsequ':145C 'system':11A,142C,146C 'trigger':46B 'unauthent':90C 'unprivileg':42B,85C 'user':8A,44B,77C,91C,124C 'v5.4.2.1':39B,73C 'version':38B,72C 'via':108C 'vulner':128C,141C 'within':74C 'without':117C","nicknames":[],"mitigations":[],"who_affected":"Applications running Hyperscan in Ring 3 user space that pass data through its matching engine are the ones exposed. Systems that do not use Hyperscan are not affected. The sources do not say which configurations or inputs are needed beyond local access.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"developers","plain_action":null,"pkeys":[],"ptokens":[],"labels":["c","hyperscan","medium","package","regex"],"campaign_type":null,"search_a":"'-2026':13A,16A '-63540':14A,17A 'buffer':3A 'crash':9A 'cve':12A,15A 'heap':2A 'hyperscan':1A 'let':5A 'local':7A 'overflow':4A 'system':11A 'user':8A","search_b":"'also':58B 'attack':48B 'base':34B 'buffer':35B 'c':18B 'caus':50B 'denial':52B 'descript':57B 'express':27B 'heap':33B 'heap-bas':32B 'hyperscan':19B,22B 'impact':62B 'integr':61B 'intel':23B 'librari':29B 'local':43B 'match':28B 'note':59B 'overflow':36B 'packag':20B 'possibl':60B 'regex':21B 'regular':26B 'regular-express':25B 'servic':54B 'trigger':46B 'unprivileg':42B 'user':44B 'v5.4.2.1':39B 'version':38B","search_c":"'3':76C 'access':110C 'adversari':87C 'allow':80C 'applic':78C 'attack':97C,112C 'avail':137C,152C 'base':65C 'buffer':66C 'combin':92C 'complex':96C 'confidenti':132C,147C 'denial':82C,100C 'enabl':99C 'heap':64C 'heap-bas':63C 'high':138C 'hyperscan':70C 'impact':130C,154C 'integr':134C,149C 'interact':125C 'intern':119C 'knowledg':120C 'local':109C 'low':95C,135C 'may':79C,98C,105C,129C 'none':133C,148C,150C,153C 'occur':107C 'overflow':67C 'passiv':123C 'potenti':106C,127C 'present':116C 'requir':113C,122C 'result':104C,143C 'ring':75C 'servic':84C,102C 'softwar':86C 'special':118C 'subsequ':145C 'system':142C,146C 'unauthent':90C 'unprivileg':85C 'user':77C,91C,124C 'v5.4.2.1':73C 'version':72C 'via':108C 'vulner':128C,141C 'within':74C 'without':117C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T18:17:45+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","cvss_by":"secure@intel.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-63540","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63540","severity":null,"published_at":"2026-11-10T18:17:45+00:00","modified_at":"2026-11-10T18:17:45+00:00","first_seen_at":"2026-11-10T18:23:01+00:00","fetched_at":"2026-11-10T18:23:01+00:00","note":null}],"documents":[],"disclosures":[],"exploit_sources":[],"notice":"Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai"}