{"vulnerability": "CVE-2026-8389", "sightings": [{"uuid": "cd4fd73e-897f-4b86-9ad6-b8afb64f626d", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "c933734a-9be8-4142-889e-26e95c752803", "vulnerability": "CVE-2026-8389", "type": "seen", "source": "https://vulnerability.circl.lu/bundle/eed1dbdf-5a0f-4cc2-9665-fa1ff05b0c1f", "content": "", "creation_timestamp": "2026-05-13T06:44:38.819942Z"}, {"uuid": "4e774716-1a1f-4856-bf03-6da7d87afa87", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2026-8389", "type": "seen", "source": "https://bsky.app/profile/cve.skyfleet.blue/post/3mlo3f3lnww2c", "content": "CVE-2026-8389 - JIT miscompilation in the JavaScript Engine: JIT component\nCVE ID : CVE-2026-8389\n \n Published : May 12, 2026, 2:17 p.m. | 13\u00a0minutes ago\n \n Description : JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 150.0....", "creation_timestamp": "2026-05-12T15:15:42.493175Z"}, {"uuid": "571274e8-8778-4771-9f8e-f158d573bf82", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "86ecb4e1-bb32-44d5-9f39-8a4673af8385", "vulnerability": "CVE-2026-8389", "type": "seen", "source": "https://www.acn.gov.it/portale/w/aggiornamenti-di-sicurezza-per-mozilla-firefox", "content": "", "creation_timestamp": "2026-05-13T06:28:15.000000Z"}, {"uuid": "87272e15-1d57-4f5b-ab8e-3e50162180d6", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2026-8389", "type": "seen", "source": "https://bsky.app/profile/getpokemon7.bsky.social/post/3mmpkrtavx224", "content": "Mozilla\u3001\u300cFirefox 150.0.3\u300d\u3092\u516c\u958b - \u8106\u5f31\u60275\u4ef6\u3092\u4fee\u6b63\n\u300cFirefox\u300d\u306b\u8907\u6570\u306e\u8106\u5f31\u6027\u304c\u5224\u660e\u3057\u3001Mozilla Foundation\u306f\u30bb\u30ad\u30e5\u30ea\u30c6\u30a3\u30a2\u30c3\u30d7\u30c7\u30fc\u30c8\u3092\u30ea\u30ea\u30fc\u30b9\u3057\u305f\u3002\n\n...\n\nJavaScript\u30a8\u30f3\u30b8\u30f3\u306e\u300cJIT\u300d\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u3067\u306f\u3001\u5883\u754c\u6761\u4ef6\u306e\u51e6\u7406\u304c\u9069\u5207\u3067\u306a\u3044\u8106\u5f31\u6027\u300cCVE-2026-8388\u300d\u3084\u3001\u8aa4\u30b3\u30f3\u30d1\u30a4\u30eb\u306e\u8106\u5f31\u6027\u300cCVE-2026-8389\u300d\u304c\u5224\u660e\u3057\u305f\u3002\u3042\u308f\u305b\u3066JavaScript\u30a8\u30f3\u30b8\u30f3\u306b\u304a\u3051\u308b\u554f\u984c\u3068\u3057\u3066\u300cCVE-2026-8391\u300d\u304c\u5224\u660e\u3057\u3066\u3044\u308b\u3002\n#\u30d1\u30c3\u30c1\u30c1\u30e5\u30fc\u30ba\u30c7\u30fc", "creation_timestamp": "2026-05-25T22:49:09.720312Z"}, {"uuid": "70d93e11-ae4e-48a4-a105-83ad4eaf687e", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2026-8389", "type": "seen", "source": "https://infosec.exchange/users/wdormann/statuses/116697621276964050", "content": "Somebody released a PoC for Firefox CVE-2026-8389, and it works.\nThe PoC doesn't include a sandbox escape, and claims that poc-win-sbx.html includes the escape.  This file was not shared in the repo.\nThe python server on localhost seems unnecessary, as the exploit web server can surely serve up primer.js the first time that payload.js is requested, and the actual payload.js the second time.  \ud83e\udd14", "creation_timestamp": "2026-06-05T12:59:48.629381Z"}, {"uuid": "3323fea7-dd0e-4ef3-be33-e748c91d82cc", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2026-8389", "type": "seen", "source": "https://bsky.app/profile/wdormann.infosec.exchange.ap.brid.gy/post/3mnk6yb6nabv2", "content": "Somebody released a PoC for Firefox CVE-2026-8389, and it works.\n\nThe PoC doesn't include a sandbox escape, and claims that `poc-win-sbx.html` includes the escape. This file was not shared in the repo.\n\nThe python server on localhost seems unnecessary, as [\u2026] \n\n[Original post on infosec.exchange]", "creation_timestamp": "2026-06-05T12:59:52.491258Z"}]}