{"cve":"CVE-2021-23973","nvd":{"published":"2021-02-26T02:15:13.243","modified":"2026-06-17T03:39:05.543","status":"Modified","description":"When trying to load a cross-origin resource in an audio/video context a decoding error may have resulted, and the content of that error may have revealed information about the resource. This vulnerability affects Firefox < 86, Thunderbird < 78.8, and Firefox ESR < 78.8.","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:N/A:N","score":6.5},"cwes":["CWE-209"],"references":["https://bugzilla.mozilla.org/show_bug.cgi?id=1690976","https://lists.debian.org/debian-lts-announce/2021/03/msg00000.html","https://security.gentoo.org/glsa/202104-09","https://security.gentoo.org/glsa/202104-10","https://www.debian.org/security/2021/dsa-4866"],"products":["debian:debian_linux","mozilla:firefox","mozilla:firefox_esr","mozilla:thunderbird"],"source":"nvd","synced_at":"2026-10-19T21:15:50.279857260+00:00"},"epss":{"cve":"CVE-2021-23973","score":0.01368,"percentile":0.7188,"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."]}