High severity7.5NVD Advisory· Published Sep 1, 2026· Updated Sep 3, 2026
CVE-2026-84145
CVE-2026-84145
Description
Internally found bugs present in Thunderbird 154, Thunderbird ESR 153.1 and Thunderbird ESR 140.14. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited. This vulnerability was fixed in Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.
Affected products
13- osv-coords11 versionspkg:rpm/opensuse/MozillaThunderbird&distro=openSUSE%20Tumbleweedpkg:apk/wolfi/firefoxpkg:apk/wolfi/firefox-docker-selenium-compatpkg:rpm/almalinux/thunderbirdpkg:rpm/opensuse/firefox-esr&distro=openSUSE%20Tumbleweedpkg:rpm/opensuse/MozillaFirefox&distro=openSUSE%20Tumbleweedpkg:rpm/almalinux/firefox-x11pkg:rpm/almalinux/firefoxpkg:apk/chainguard/firefoxpkg:apk/chainguard/firefox-docker-selenium-compatpkg:rpm/opensuse/MozillaFirefox&distro=openSUSE%20Leap%2016.0
< 140.15.0-1.1+ 10 more
- (no CPE)range: < 140.15.0-1.1
- (no CPE)range: < 155.0.1-r0
- (no CPE)range: < 155.0.1-r0
- (no CPE)range: < 140.16.0-1.el9_8.alma.1
- (no CPE)range: < 153.2.0-1.1
- (no CPE)range: < 155.0-1.1
- (no CPE)range: < 140.15.0-1.el9_8.alma.1
- (no CPE)range: < 140.15.0-1.el10_2
- (no CPE)range: < 155.0.1-r0
- (no CPE)range: < 155.0.1-r0
- (no CPE)range: < 153.2.0-160000.1.1
Patches
Vulnerability mechanics
References
10- www.mozilla.org/security/advisories/mfsa2026-82/nvdVendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-83/nvdVendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-84/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/mfsa2026-87/nvdVendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-88/nvdVendor Advisory
- bugzilla.mozilla.org/buglist.cginvdBroken Link
- bugzilla.mozilla.org/buglist.cginvdBroken Link
- bugzilla.mozilla.org/show_bug.cginvdPermissions Required
News mentions
2- Mozilla Thunderbird: 16 Vulnerabilities Including Critical Sandbox Escapes Disclosed TogetherVypr Intelligence · Sep 1, 2026
- Mozilla Firefox & Thunderbird: 25 Vulnerabilities Including Critical Sandbox Escapes Disclosed TogetherVypr Intelligence · Sep 1, 2026