CVE-2026-84143: Vulnerability in Mozilla Firefox
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 140.15, Firefox ESR 153.2, Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.
CVE-2026-84143: Vulnerability in Mozilla Firefox
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 140.15, Firefox ESR 153.2, Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-09-01T07:26:01.305Z
- Cvss Version
- null
- State
- PUBLISHED
- Remediation Level
- null
- Vendor Advisory Urls
- [{"url":"https://www.mozilla.org/security/advisories/mfsa2026-82/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-84/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-85/","vendor":"Mozilla"}]
Threat ID: 6a96cab4acd9273b49b685ab
Added to database: 09/01/2026, 12:53:08 UTC
Last updated: 09/02/2026, 02:10:22 UTC
Views: 10
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