{"id":"CVE-2026-40694","kind":"vulnerability","aliases":["CVE-2026-40694"],"related":[],"title":"Hyperscan: out-of-bounds write lets a local user crash applications","description":"Out-of-bounds write 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 authenticated user combined with a low complexity attack may enable denial of service. This result may potentially occur via local access when attack requirements are present without special internal knowledge and requires no user interaction. The potential vulnerability may impact the confidentiality (low), 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 an out-of-bounds write in versions before v5.4.2.1 that can be triggered from user-level code. An attacker with an authenticated local account can cause a denial of service by crashing the application that uses it.","severity":"medium","cvss":5.8,"epss":null,"exploited":false,"exploited_at":null,"products":[{"name":"Hyperscan","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["hyperscan","local-users","multi-tenant","package"],"not_affected_if":["hyperscan-v5.4.2.1-or-later","no-untrusted-local-users"],"how_to_check":"- Check the Hyperscan version your application links against, for example with `pkg-config --modversion libhs` or the version pinned in your build files.\n- Identify whether any local, unprivileged users can submit input to processes that use Hyperscan.","fix":"- Hyperscan: move to `v5.4.2.1` or later","status":"open","published_at":"2026-11-10T18:17:38+00:00","first_seen_at":"2026-11-10T18:22:57+00:00","triaged_at":"2026-11-10T18:25:04+00:00","updated_at":"2026-11-10T18:25:04+00:00","category":"package","confidence":0.6,"triage":{"at":"2026-11-10T18:25:04Z","model":"claude-haiku-5-5","output":{"fix":"- Hyperscan: move to `v5.4.2.1` or later","reach":"local","title":"Hyperscan: out-of-bounds write lets a local user crash applications","impact":"low","summary":"Hyperscan, Intel's regular expression matching library, has an out-of-bounds write in versions before v5.4.2.1 that can be triggered from user-level code. An attacker with an authenticated local account can cause a denial of service by crashing the application that uses it.","audience":"developers","category":"package","nicknames":[],"who_cares":["hyperscan","local-users","multi-tenant"],"confidence":0.6,"fix_status":"available","needs_auth":"yes","worst_case":"Denial of service by crashing the Hyperscan-using process","analyst_note":"","how_to_check":"- Check the Hyperscan version your application links against, for example with `pkg-config --modversion libhs` or the version pinned in your build files.\n- Identify whether any local, unprivileged users can submit input to processes that use Hyperscan.","plain_action":"","product_name":"Hyperscan","needs_analyst":false,"not_affected_if":["hyperscan-v5.4.2.1-or-later","no-untrusted-local-users"],"who_is_affected":"Applications that embed Hyperscan and let local authenticated users drive its pattern matching. Systems where Hyperscan is only used on trusted input by trusted users are lower risk. unknown whether the sources describe a specific default configuration.","user_interaction":"no","product_ecosystem":"vendor","needs_special_setup":"unknown","severity_if_unknown":"medium"},"cost_usd":0.000743,"input_tokens":4655,"output_tokens":554,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-2026':14A,17A '-40694':15A,18A '3':87C 'access':121C 'account':61B 'adversari':98C 'allow':91C 'applic':12A,71B,89C 'attack':56B,108C,123C 'authent':59B,101C 'avail':147C,162C 'bound':5A,40B,77C 'caus':63B 'code':54B 'combin':103C 'complex':107C 'confidenti':142C,157C 'crash':11A,69B 'cve':13A,16A 'denial':65B,93C,111C 'enabl':110C 'express':32B 'high':148C 'hyperscan':1A,19A,20B,28B,81C 'impact':140C,164C 'integr':144C,159C 'intel':29B 'interact':135C 'intern':129C 'knowledg':130C 'let':7A 'level':53B 'librari':34B 'local':9A,22B,60B,120C 'local-us':21B 'low':106C,143C,145C 'match':33B 'may':90C,109C,116C,139C 'multi':25B 'multi-ten':24B 'none':158C,160C,163C 'occur':118C 'out-of-bound':2A,37B,74C 'packag':27B 'potenti':117C,137C 'present':126C 'regular':31B 'requir':124C,132C 'result':115C,153C 'ring':86C 'servic':67B,95C,113C 'softwar':97C 'special':128C 'subsequ':155C 'system':152C,156C 'tenant':26B 'trigger':49B 'unprivileg':96C 'use':73B 'user':10A,23B,52B,88C,102C,134C 'user-level':51B 'v5.4.2.1':45B,84C 'version':43B,83C 'via':119C 'vulner':138C,151C 'within':85C 'without':127C 'write':6A,41B,78C","nicknames":[],"mitigations":[],"who_affected":"Applications that embed Hyperscan and let local authenticated users drive its pattern matching. Systems where Hyperscan is only used on trusted input by trusted users are lower risk. unknown whether the sources describe a specific default configuration.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"developers","plain_action":null,"pkeys":["hyperscan"],"ptokens":["hyperscan"],"labels":["hyperscan","localusers","medium","multitenant","package","vendor"],"campaign_type":null,"search_a":"'-2026':14A,17A '-40694':15A,18A 'applic':12A 'bound':5A 'crash':11A 'cve':13A,16A 'hyperscan':1A,19A 'let':7A 'local':9A 'out-of-bound':2A 'user':10A 'write':6A","search_b":"'account':61B 'applic':71B 'attack':56B 'authent':59B 'bound':40B 'caus':63B 'code':54B 'crash':69B 'denial':65B 'express':32B 'hyperscan':20B,28B 'intel':29B 'level':53B 'librari':34B 'local':22B,60B 'local-us':21B 'match':33B 'multi':25B 'multi-ten':24B 'out-of-bound':37B 'packag':27B 'regular':31B 'servic':67B 'tenant':26B 'trigger':49B 'use':73B 'user':23B,52B 'user-level':51B 'v5.4.2.1':45B 'version':43B 'write':41B","search_c":"'3':87C 'access':121C 'adversari':98C 'allow':91C 'applic':89C 'attack':108C,123C 'authent':101C 'avail':147C,162C 'bound':77C 'combin':103C 'complex':107C 'confidenti':142C,157C 'denial':93C,111C 'enabl':110C 'high':148C 'hyperscan':81C 'impact':140C,164C 'integr':144C,159C 'interact':135C 'intern':129C 'knowledg':130C 'local':120C 'low':106C,143C,145C 'may':90C,109C,116C,139C 'none':158C,160C,163C 'occur':118C 'out-of-bound':74C 'potenti':117C,137C 'present':126C 'requir':124C,132C 'result':115C,153C 'ring':86C 'servic':95C,113C 'softwar':97C 'special':128C 'subsequ':155C 'system':152C,156C 'unprivileg':96C 'user':88C,102C,134C 'v5.4.2.1':84C 'version':83C 'via':119C 'vulner':138C,151C 'within':85C 'without':127C 'write':78C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T18:17:38+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:L/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-2026-40694","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-40694","severity":null,"published_at":"2026-11-10T18:17:38+00:00","modified_at":"2026-11-10T18:17:38+00:00","first_seen_at":"2026-11-10T18:22:57+00:00","fetched_at":"2026-11-10T18:22:57+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"}