{"id":"DEBIAN-CVE-2020-26958","details":"Firefox did not block execution of scripts with incorrect MIME types when the response was intercepted and cached through a ServiceWorker. This could lead to a cross-site script inclusion vulnerability, or a Content Security Policy bypass. This vulnerability affects Firefox \u003c 83, Firefox ESR \u003c 78.5, and Thunderbird \u003c 78.5.","modified":"2026-09-01T16:05:00.660778312Z","published":"2020-12-09T01:15:13.080Z","upstream":["CVE-2020-26958"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2020-26958"}],"affected":[{"package":{"name":"firefox-esr","ecosystem":"Debian:12","purl":"pkg:deb/debian/firefox-esr?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"78.5.0esr-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2020-26958.json"}},{"package":{"name":"firefox-esr","ecosystem":"Debian:13","purl":"pkg:deb/debian/firefox-esr?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"78.5.0esr-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2020-26958.json"}},{"package":{"name":"firefox-esr","ecosystem":"Debian:14","purl":"pkg:deb/debian/firefox-esr?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"78.5.0esr-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2020-26958.json"}},{"package":{"name":"thunderbird","ecosystem":"Debian:12","purl":"pkg:deb/debian/thunderbird?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:78.5.0-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2020-26958.json"}},{"package":{"name":"thunderbird","ecosystem":"Debian:13","purl":"pkg:deb/debian/thunderbird?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:78.5.0-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2020-26958.json"}},{"package":{"name":"thunderbird","ecosystem":"Debian:14","purl":"pkg:deb/debian/thunderbird?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:78.5.0-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2020-26958.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"}]}