{"id":"CVE-2026-12067","aliases":["EUVD-2026-118327","GHSA-fpp4-5g35-6qq3"],"status":"published","title":"AvastSvc denial of service via unhandled JsonCpp exceptions in native message handlers","description":"Missing exception handlers in AvastSvc native message dispatcher (ashServ.dll) on Windows allow a local, unprivileged attacker to crash the service by sending specially crafted JSON messages.\n\n\n\nThe vulnerability spans multiple handler pathways in the RPC-based native message protocol:\n\n  *  Log_NmSvc.message handler: converts JSON fields to strings without type validation and without exception boundaries. \n  *  OpenInSz_NmSvc handler: converts URL and origin fields to strings without type checking, exposing an exception.\n  *  OpenInSz_NmSvc.profile handler: converts the profile field to an integer without validation.\n\n\nIn all three cases, the exceptions are not caught by action-specific handlers and propagate up the dispatcher. The common root cause is the absence of try-catch blocks around JSON type conversions in the native message processing chain.","severity":{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"adp","from":"cve"},"epss":{"day":"2026-11-12","score":0.00305,"percentile":0.23592,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-248","CWE-391"],"published":"2026-11-06T15:57:54Z","modified":"2026-11-10T18:34:51Z","products":[{"vendor":"gen digital","product":"avast antivirus, avast one, avast premium security, avast ultimate, avast business security"},{"vendor":"gen digital","product":"avg antivirus free, avg internet security, avg ultimate"},{"vendor":"gen digital","product":"norton antivirus plus, norton 360 standard, norton 360 deluxe, norton 360 advanced"}],"references":[{"url":"https://www.gendigital.com/us/en/contact-us/security-advisories/","tags":["vendor-advisory"]},{"url":"https://support.avast.com/en-us/article/Update-Antivirus","tags":["patch"]},{"url":"https://support.avg.com/SupportArticleView?l=en\u0026urlname=Update-AVG-Antivirus","tags":["patch"]},{"url":"https://support.norton.com/sp/en/us/home/current/solutions/v20240108175512167","tags":["patch"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-12067"},{"url":"https://www.gendigital.com/us/en/contact-us/security-advisories"},{"url":"https://github.com/advisories/GHSA-fpp4-5g35-6qq3"}],"sources":{"cve":[{"id":"CVE-2026-12067","title":"AvastSvc denial of service via unhandled JsonCpp exceptions in native message handlers","description":"Missing exception handlers in AvastSvc native message dispatcher (ashServ.dll) on Windows allow a local, unprivileged attacker to crash the service by sending specially crafted JSON messages.\n\n\n\nThe vulnerability spans multiple handler pathways in the RPC-based native message protocol:\n\n  *  Log_NmSvc.message handler: converts JSON fields to strings without type validation and without exception boundaries. \n  *  OpenInSz_NmSvc handler: converts URL and origin fields to strings without type checking, exposing an exception.\n  *  OpenInSz_NmSvc.profile handler: converts the profile field to an integer without validation.\n\n\nIn all three cases, the exceptions are not caught by action-specific handlers and propagate up the dispatcher. The common root cause is the absence of try-catch blocks around JSON type conversions in the native message processing chain.","status":"published","published":"2026-11-06T15:57:54.623Z","modified":"2026-11-10T18:34:51.398Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"adp"}],"cwes":["CWE-248","CWE-391"],"updated_at":"2026-11-10T19:39:58.973959Z"}],"euvd":[{"id":"EUVD-2026-118327","description":"Missing exception handlers in AvastSvc native message dispatcher (ashServ.dll) on Windows allow a local, unprivileged attacker to crash the service by sending specially crafted JSON messages.\n\n\n\nThe vulnerability spans multiple handler pathways in the RPC-based native message protocol:\n\n  *  Log_NmSvc.message handler: converts JSON fields to strings without type validation and without exception boundaries. \n  *  OpenInSz_NmSvc handler: converts URL and origin fields to strings without type checking, exposing an exception.\n  *  OpenInSz_NmSvc.profile handler: converts the profile field to an integer without validation.\n\n\nIn all three cases, the exceptions are not caught by action-specific handlers and propagate up the dispatcher. The common root cause is the absence of try-catch blocks around JSON type conversions in the native message processing chain.","status":"published","published":"2026-11-06T15:57:54Z","modified":"2026-11-10T18:34:51Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-10T19:22:06.032365Z"}],"ghsa":[{"id":"GHSA-fpp4-5g35-6qq3","title":"Missing exception handlers in AvastSvc native message dispatcher (ashServ.dll) on Windows allow a...","description":"Missing exception handlers in AvastSvc native message dispatcher (ashServ.dll) on Windows allow a local, unprivileged attacker to crash the service by sending specially crafted JSON messages.\n\n\n\nThe vulnerability spans multiple handler pathways in the RPC-based native message protocol:\n\n  *  Log_NmSvc.message handler: converts JSON fields to strings without type validation and without exception boundaries. \n  *  OpenInSz_NmSvc handler: converts URL and origin fields to strings without type checking, exposing an exception.\n  *  OpenInSz_NmSvc.profile handler: converts the profile field to an integer without validation.\n\n\nIn all three cases, the exceptions are not caught by action-specific handlers and propagate up the dispatcher. The common root cause is the absence of try-catch blocks around JSON type conversions in the native message processing chain.","status":"published","published":"2026-11-06T18:35:13Z","modified":"2026-11-10T21:32:55Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"cwes":["CWE-248"],"updated_at":"2026-11-10T21:57:51.137748Z"}],"nvd":[{"id":"CVE-2026-12067","description":"Missing exception handlers in AvastSvc native message dispatcher (ashServ.dll) on Windows allow a local, unprivileged attacker to crash the service by sending specially crafted JSON messages.\n\n\n\nThe vulnerability spans multiple handler pathways in the RPC-based native message protocol:\n\n  *  Log_NmSvc.message handler: converts JSON fields to strings without type validation and without exception boundaries. \n  *  OpenInSz_NmSvc handler: converts URL and origin fields to strings without type checking, exposing an exception.\n  *  OpenInSz_NmSvc.profile handler: converts the profile field to an integer without validation.\n\n\nIn all three cases, the exceptions are not caught by action-specific handlers and propagate up the dispatcher. The common root cause is the absence of try-catch blocks around JSON type conversions in the native message processing chain.","status":"published","published":"2026-11-06T16:17:55.64Z","modified":"2026-11-10T19:21:14.417Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"secondary"}],"cwes":["CWE-248","CWE-391"],"updated_at":"2026-11-10T22:21:31.83577Z"}]}}