CVE-2026-84143
Internally found bugs fixed in Firefox 155, Firefox ESR 153.2 and Firefox ESR 140.15
Description
Internally found bugs present in Firefox 154, Firefox ESR 153.1 and Firefox 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, and Firefox ESR 153.2.
INFO
Published Date :
Sept. 1, 2026, 1:20 p.m.
Last Modified :
Sept. 1, 2026, 1:20 p.m.
Remotely Exploit :
No
Source :
[email protected]
Solution
- Update Firefox to version 155.
- Update Firefox ESR to version 153.2.
- Update Firefox ESR to version 140.15.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-84143.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-84143 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-84143
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-84143 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-84143 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
Sep. 01, 2026
Action Type Old Value New Value Added Description Internally found bugs present in Firefox 154, Firefox ESR 153.1 and Firefox 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, and Firefox ESR 153.2. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/84xxx/CVE-2026-84143.json">CVE-2026-84143</a> Added Reference https://bugzilla.mozilla.org/buglist.cgi?bug_id=2048793%2C2054645%2C2057114%2C2059109%2C2061287 Added Reference https://bugzilla.mozilla.org/buglist.cgi?bug_id=2054631%2C2054657%2C2055007%2C2055681%2C2057107%2C2058087%2C2058088%2C2058090%2C2058095%2C2058101%2C2059183%2C2059185%2C2061301%2C2061325 Added Reference https://bugzilla.mozilla.org/show_bug.cgi?id=2057108 Added Reference https://www.mozilla.org/security/advisories/mfsa2026-82/ Added Reference https://www.mozilla.org/security/advisories/mfsa2026-84/ Added Reference https://www.mozilla.org/security/advisories/mfsa2026-85/