{"id":"CVE-2026-117863","kind":"vulnerability","aliases":["CVE-2026-117863"],"related":[],"title":"Firefox: uninitialized memory in Audio/Video leaks data to attackers","description":"Information disclosure due to uninitialized memory in the Audio/Video component. This vulnerability was fixed in Firefox 159, Firefox ESR 115.44, and Firefox ESR 153.6.","summary":"Firefox's Audio/Video component can expose uninitialized memory, which can leak fragments of other process data. The sources do not describe the exact trigger, so the attacker's reach beyond information disclosure is unknown.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["browsers","desktop","firefox","runtime"],"not_affected_if":["already-patched-version"],"how_to_check":"- Run `firefox --version` (or check the About Firefox page) and compare against the fixed versions\n- Check ESR installs for `115.44` or `153.6` or later\n- unknown for other checks, as the sources do not say","fix":"- Update Firefox to `159` or later\n- Update Firefox ESR 115 to `115.44` or later\n- Update Firefox ESR 153 to `153.6` or later","status":"open","published_at":"2026-10-27T14:16:40+00:00","first_seen_at":"2026-10-27T14:32:21+00:00","triaged_at":"2026-10-27T14:39:22+00:00","updated_at":"2026-10-27T14:39:22+00:00","category":"runtime","confidence":0.5,"triage":{"at":"2026-10-27T14:39:22Z","model":"claude-haiku-5-5","output":{"fix":"- Update Firefox to `159` or later\n- Update Firefox ESR 115 to `115.44` or later\n- Update Firefox ESR 153 to `153.6` or later","reach":"unknown","title":"Firefox: uninitialized memory in Audio/Video leaks data to attackers","impact":"low","summary":"Firefox's Audio/Video component can expose uninitialized memory, which can leak fragments of other process data. The sources do not describe the exact trigger, so the attacker's reach beyond information disclosure is unknown.","category":"runtime","nicknames":[],"who_cares":["firefox","browsers","desktop"],"confidence":0.5,"needs_auth":"unknown","worst_case":"Attacker reads fragments of uninitialized browser memory","analyst_note":"Check the Mozilla security advisory for this CVE for the trigger, the affected media path, and whether it is web-reachable.","how_to_check":"- Run `firefox --version` (or check the About Firefox page) and compare against the fixed versions\n- Check ESR installs for `115.44` or `153.6` or later\n- unknown for other checks, as the sources do not say","needs_analyst":true,"not_affected_if":["already-patched-version"],"who_is_affected":"Anyone running a Firefox build older than the fixed versions, including ESR installs on 115 and 153 branches. The sources do not say whether a specific configuration or media setting is required, so the exposure window is unknown. Teams that only use managed browsers with automatic updates are likely covered once updates have rolled out.","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"unknown"},"cost_usd":0.000612,"input_tokens":3264,"output_tokens":572,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-117863':12A,15A '-2026':11A,14A '115.44':73C '153.6':77C '159':70C 'attack':9A,46B 'audio/video':5A,22B,62C 'beyond':49B 'browser':16B 'compon':23B,63C 'cve':10A,13A 'data':7A,35B 'describ':40B 'desktop':17B 'disclosur':51B,55C 'due':56C 'esr':72C,76C 'exact':42B 'expos':25B 'firefox':1A,18B,20B,69C,71C,75C 'fix':67C 'fragment':31B 'inform':50B,54C 'leak':6A,30B 'memori':3A,27B,59C 'process':34B 'reach':48B 'runtim':19B 'sourc':37B 'trigger':43B 'uniniti':2A,26B,58C 'unknown':53B 'vulner':65C","nicknames":[],"mitigations":[],"who_affected":"Anyone running a Firefox build older than the fixed versions, including ESR installs on 115 and 153 branches. The sources do not say whether a specific configuration or media setting is required, so the exposure window is unknown. Teams that only use managed browsers with automatic updates are likely covered once updates have rolled out.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-27T14:16:40+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-117863","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-117863","severity":null,"published_at":"2026-10-27T14:16:40+00:00","modified_at":"2026-10-27T14:16:40+00:00","first_seen_at":"2026-10-27T14:32:21+00:00","fetched_at":"2026-10-27T14:32:21+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"}