{"cve":"CVE-2020-15656","nvd":{"published":"2020-08-10T18:15:12.547","modified":"2026-06-17T02:56:59.750","status":"Modified","description":"JIT optimizations involving the Javascript arguments object could confuse later optimizations. This risk was already mitigated by various precautions in the code, resulting in this bug rated at only moderate severity. This vulnerability affects Firefox ESR < 78.1, Firefox < 79, and Thunderbird < 78.1.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","score":8.8},"cwes":["CWE-843"],"references":["http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00025.html","https://bugzilla.mozilla.org/show_bug.cgi?id=1647293","https://usn.ubuntu.com/4443-1/","https://www.mozilla.org/security/advisories/mfsa2020-30/","https://www.mozilla.org/security/advisories/mfsa2020-32/"],"products":["canonical:ubuntu_linux","mozilla:firefox","mozilla:firefox_esr","mozilla:thunderbird","opensuse:leap"],"source":"nvd","synced_at":"2026-10-19T21:06:22.076270124+00:00"},"epss":{"cve":"CVE-2020-15656","score":0.01523,"percentile":0.74643,"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."]}