Medium severity6.1NVD Advisory· Published Sep 1, 2026· Updated Sep 3, 2026
CVE-2026-84139
CVE-2026-84139
Description
Clickjacking issue in the DOM: Events component. This vulnerability was fixed in Firefox 155, Firefox ESR 153.2, Thunderbird 155, and Thunderbird 153.2.
Affected products
8- Range: >=155
- Range: >=153.2
- osv-coords6 versionspkg:rpm/opensuse/MozillaFirefox&distro=openSUSE%20Tumbleweedpkg:rpm/opensuse/firefox-esr&distro=openSUSE%20Tumbleweedpkg:apk/chainguard/firefox-docker-selenium-compatpkg:apk/wolfi/firefox-docker-selenium-compatpkg:rpm/opensuse/MozillaFirefox&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/MozillaThunderbird&distro=openSUSE%20Tumbleweed
< 155.0-1.1+ 5 more
- (no CPE)range: < 155.0-1.1
- (no CPE)range: < 153.2.0-1.1
- (no CPE)range: < 155.0.1-r0
- (no CPE)range: < 155.0.1-r0
- (no CPE)range: < 153.2.0-160000.1.1
- (no CPE)range: < 153.4.0-1.1
Patches
Vulnerability mechanics
References
5- www.mozilla.org/security/advisories/mfsa2026-82/nvdVendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-85/nvdVendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-86/nvdVendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-88/nvdVendor Advisory
- bugzilla.mozilla.org/show_bug.cginvdIssue TrackingPermissions Required
News mentions
1- Mozilla Firefox & Thunderbird: 25 Vulnerabilities Including Critical Sandbox Escapes Disclosed TogetherVypr Intelligence · Sep 1, 2026