{"cve":"CVE-2020-12421","nvd":{"published":"2020-07-09T15:15:12.053","modified":"2026-06-17T02:51:48.340","status":"Modified","description":"When performing add-on updates, certificate chains terminating in non-built-in-roots were rejected (even if they were legitimately added by an administrator.) This could have caused add-ons to become out-of-date silently without notification to the user. This vulnerability affects Firefox ESR < 68.10, Firefox < 78, and Thunderbird < 68.10.0.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N","score":6.5},"cwes":["CWE-295"],"references":["http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00023.html","http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00026.html","http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00027.html","http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00049.html","https://bugzilla.mozilla.org/show_bug.cgi?id=1308251"],"products":["canonical:ubuntu_linux","mozilla:firefox","mozilla:firefox_esr","mozilla:thunderbird"],"source":"nvd","synced_at":"2026-10-19T21:06:22.076270124+00:00"},"epss":{"cve":"CVE-2020-12421","score":0.01843,"percentile":0.79025,"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."]}