{"id":"CVE-2026-117969","kind":"vulnerability","aliases":["CVE-2026-117969"],"related":[],"title":"Firefox: JavaScript JIT invalid pointer may allow memory corruption","description":"Invalid pointer in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 159 and Firefox ESR 153.6.","summary":"Firefox's JavaScript engine JIT compiler handles a pointer incorrectly. The sources do not describe what an attacker can achieve beyond that, but memory corruption in a JIT typically risks code execution in the browser.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["browsers","desktop","firefox","runtime"],"not_affected_if":["already-on-fixed-version"],"how_to_check":"- Check the installed Firefox version via Help > About Firefox, or `firefox --version`.\n- Check whether the ESR channel is in use, with ESR builds at `153.6` or later being patched.","fix":"- Update Firefox to `159` or later.\n- Update Firefox ESR to `153.6` or later.","status":"open","published_at":"2026-10-27T14:16:54+00:00","first_seen_at":"2026-10-27T14:32:24+00:00","triaged_at":"2026-10-27T14:35:19+00:00","updated_at":"2026-10-27T14:35:19+00:00","category":"runtime","confidence":0.5,"triage":{"at":"2026-10-27T14:35:19Z","model":"claude-haiku-5-5","output":{"fix":"- Update Firefox to `159` or later.\n- Update Firefox ESR to `153.6` or later.","reach":"internet","title":"Firefox: JavaScript JIT invalid pointer may allow memory corruption","impact":"high","summary":"Firefox's JavaScript engine JIT compiler handles a pointer incorrectly. The sources do not describe what an attacker can achieve beyond that, but memory corruption in a JIT typically risks code execution in the browser.","category":"runtime","nicknames":[],"who_cares":["firefox","browsers","desktop"],"confidence":0.5,"needs_auth":"no","worst_case":"unknown","analyst_note":"Confirm from Mozilla's advisory whether the bug is exploitable from web content and whether it is known to be exploited, since the NVD entry gives no severity.","how_to_check":"- Check the installed Firefox version via Help > About Firefox, or `firefox --version`.\n- Check whether the ESR channel is in use, with ESR builds at `153.6` or later being patched.","needs_analyst":true,"not_affected_if":["already-on-fixed-version"],"who_is_affected":"Anyone running desktop or ESR Firefox builds older than the fixed versions is exposed, since the flaw is in the browser's JavaScript engine. Managed fleets pinned to older ESR lines should prioritize updating. Systems that do not run Firefox are not affected.","user_interaction":"yes","needs_special_setup":"no","severity_if_unknown":"unknown"},"cost_usd":0.000588,"input_tokens":3248,"output_tokens":527,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-117969':12A,15A '-2026':11A,14A '153.6':73C '159':69C 'achiev':39B 'allow':7A 'attack':37B 'beyond':40B 'browser':16B,54B 'code':50B 'compil':25B 'compon':62C 'corrupt':9A,44B 'cve':10A,13A 'describ':34B 'desktop':17B 'engin':23B,60C 'esr':72C 'execut':51B 'firefox':1A,18B,20B,68C,71C 'fix':66C 'handl':26B 'incorrect':29B 'invalid':4A,55C 'javascript':2A,22B,59C 'jit':3A,24B,47B,61C 'may':6A 'memori':8A,43B 'pointer':5A,28B,56C 'risk':49B 'runtim':19B 'sourc':31B 'typic':48B 'vulner':64C","nicknames":[],"mitigations":[],"who_affected":"Anyone running desktop or ESR Firefox builds older than the fixed versions is exposed, since the flaw is in the browser's JavaScript engine. Managed fleets pinned to older ESR lines should prioritize updating. Systems that do not run Firefox are not affected.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-27T14:16:54+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-117969","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-117969","severity":null,"published_at":"2026-10-27T14:16:54+00:00","modified_at":"2026-10-27T14:16:54+00:00","first_seen_at":"2026-10-27T14:32:24+00:00","fetched_at":"2026-10-27T14:32:24+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"}