{"cve":"CVE-2016-5284","nvd":{"published":"2016-09-22T22:59:18.973","modified":"2026-06-17T00:49:07.083","status":"Modified","description":"Mozilla Firefox before 49.0, Firefox ESR 45.x before 45.4, and Thunderbird < 45.4 rely on unintended expiration dates for Preloaded Public Key Pinning, which allows man-in-the-middle attackers to spoof add-on updates by leveraging possession of an X.509 server certificate for addons.mozilla.org signed by an arbitrary built-in Certification Authority.","cvss_v4":null,"cvss_v3":{"version":"3.0","vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N","score":7.4},"cwes":["CWE-20"],"references":["http://rhn.redhat.com/errata/RHSA-2016-1912.html","http://seclists.org/dailydave/2016/q3/51","http://www.debian.org/security/2016/dsa-3674","http://www.mozilla.org/security/announce/2016/mfsa2016-85.html","http://www.oracle.com/technetwork/topics/security/linuxbulletinoct2016-3090545.html"],"products":["mozilla:firefox"],"source":"nvd","synced_at":"2026-10-19T20:40:10.783210791+00:00"},"epss":{"cve":"CVE-2016-5284","score":0.02373,"percentile":0.8385,"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."]}