{"cve":"CVE-2019-9821","nvd":{"published":"2019-07-23T14:15:17.483","modified":"2026-06-17T02:44:40.087","status":"Modified","description":"A use-after-free vulnerability can occur in AssertWorkerThread due to a race condition with shared workers. This results in a potentially exploitable crash. This vulnerability affects Firefox < 67.","cvss_v4":null,"cvss_v3":{"version":"3.0","vector":"CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","score":8.1},"cwes":["CWE-362","CWE-416"],"references":["https://bugzilla.mozilla.org/show_bug.cgi?id=1539125","https://www.mozilla.org/security/advisories/mfsa2019-13/","https://bugzilla.mozilla.org/show_bug.cgi?id=1539125","https://www.mozilla.org/security/advisories/mfsa2019-13/"],"products":["mozilla:firefox"],"source":"nvd","synced_at":"2026-10-19T20:58:11.797917892+00:00"},"epss":{"cve":"CVE-2019-9821","score":0.00846,"percentile":0.58062,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}