{"id":"CVE-2026-124872","kind":"vulnerability","aliases":["CVE-2026-124872"],"related":[],"title":"Firefox: use-after-free bug in the Cycle Collector component","description":"Use-after-free in the Cycle Collector component. This vulnerability was fixed in Firefox 160, Firefox ESR 115.45, and Firefox ESR 153.7.","summary":"Firefox has a use-after-free bug in its Cycle Collector component, which handles memory cleanup for objects. The sources do not state what an attacker can do with it.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["browser","firefox","other"],"not_affected_if":["already-on-fixed-version"],"how_to_check":"- Check the Firefox version with `about:support` or Help > About Firefox, and compare it with the fixed versions below.\n- Check whether an ESR install is on `115.x` or `153.x`, since each branch has its own fixed version.","fix":"- Firefox: `160`\n- Firefox ESR: `115.45`\n- Firefox ESR: `153.7`","status":"open","published_at":"2026-11-10T14:17:19+00:00","first_seen_at":"2026-11-10T14:22:14+00:00","triaged_at":"2026-11-10T14:26:26+00:00","updated_at":"2026-11-10T14:26:26+00:00","category":"other","confidence":0.5,"triage":{"at":"2026-11-10T14:26:26Z","model":"claude-haiku-5-5","output":{"fix":"- Firefox: `160`\n- Firefox ESR: `115.45`\n- Firefox ESR: `153.7`","reach":"unknown","title":"Firefox: use-after-free bug in the Cycle Collector component","impact":"high","summary":"Firefox has a use-after-free bug in its Cycle Collector component, which handles memory cleanup for objects. The sources do not state what an attacker can do with it.","audience":"everyone","category":"other","nicknames":[],"who_cares":["firefox","browser"],"confidence":0.5,"fix_status":"available","needs_auth":"no","worst_case":"unknown; the sources do not state what an attacker gains","analyst_note":"","how_to_check":"- Check the Firefox version with `about:support` or Help > About Firefox, and compare it with the fixed versions below.\n- Check whether an ESR install is on `115.x` or `153.x`, since each branch has its own fixed version.","plain_action":"Update Firefox to version 160 or later (or the matching ESR version: 115.45 or 153.7).","product_name":"","needs_analyst":false,"not_affected_if":["already-on-fixed-version"],"who_is_affected":"Anyone running a vulnerable Firefox release or ESR branch is affected. The sources do not say which configurations or browsing paths trigger the bug.","user_interaction":"unknown","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"unknown"},"cost_usd":0.00112,"input_tokens":4484,"output_tokens":1343,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-124872':14A,17A '-2026':13A,16A '115.45':65C '153.7':69C '160':62C 'attack':46B 'browser':18B 'bug':6A,27B 'cleanup':36B 'collector':10A,31B,54C 'compon':11A,32B,55C 'cve':12A,15A 'cycl':9A,30B,53C 'esr':64C,68C 'firefox':1A,19B,20B,61C,63C,67C 'fix':59C 'free':5A,26B,50C 'handl':34B 'memori':35B 'object':38B 'sourc':40B 'state':43B 'use':3A,24B,48C 'use-after-fre':2A,23B,47C 'vulner':57C","nicknames":[],"mitigations":[],"who_affected":"Anyone running a vulnerable Firefox release or ESR branch is affected. The sources do not say which configurations or browsing paths trigger the bug.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"everyone","plain_action":"Update Firefox to version 160 or later (or the matching ESR version: 115.45 or 153.7).","pkeys":[],"ptokens":[],"labels":["browser","firefox","other","unknown"],"campaign_type":null,"search_a":"'-124872':14A,17A '-2026':13A,16A 'bug':6A 'collector':10A 'compon':11A 'cve':12A,15A 'cycl':9A 'firefox':1A 'free':5A 'use':3A 'use-after-fre':2A","search_b":"'attack':46B 'browser':18B 'bug':27B 'cleanup':36B 'collector':31B 'compon':32B 'cycl':30B 'firefox':19B,20B 'free':26B 'handl':34B 'memori':35B 'object':38B 'sourc':40B 'state':43B 'use':24B 'use-after-fre':23B","search_c":"'115.45':65C '153.7':69C '160':62C 'collector':54C 'compon':55C 'cycl':53C 'esr':64C,68C 'firefox':61C,63C,67C 'fix':59C 'free':50C 'use':48C 'use-after-fre':47C 'vulner':57C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T14:17:19+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-124872","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-124872","severity":null,"published_at":"2026-11-10T14:17:19+00:00","modified_at":"2026-11-10T14:17:19+00:00","first_seen_at":"2026-11-10T14:22:14+00:00","fetched_at":"2026-11-10T14:22:14+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"}