Security Alert (A26-09-46): Multiple Vulnerabilities in Firefox


 

Published on: 30 September 2026

Description:

Mozilla has published the advisories (MFSA2026-100, MFSA2026-97, MFSA2026-98 and MFSA2026-99) to address multiple vulnerabilities in Firefox. A remote attacker could entice a user to open a web page with specially crafted content on a vulnerable browser to exploit the vulnerabilities.

 

Affected Systems:

  • Firefox ESR Windows versions prior to version 115.42, 140.17, 153.4
  • Firefox Windows versions prior to version 157

 

Impact:

Successful exploitation of the vulnerability could lead to denial of service, elevation of privilege, information disclosure, security restriction bypass or spoofing on an affected system.

 

Recommendation:

Mozilla has released new versions of the product to address the issues and they can be downloaded at the following URLs:
Firefox 157 (Windows)
https://www.mozilla.org/en-US/firefox/all/#product-desktop-release
Firefox ESR 115.42, 140.17, 153.4 (Windows)
https://www.mozilla.org/en-US/firefox/all/#product-desktop-esr

Users of affected systems should follow the recommendations provided by the vendor and take immediate actions to mitigate the risk.

 

More Information:

  • https://www.mozilla.org/en-US/security/advisories/mfsa2026-100/
  • https://www.mozilla.org/en-US/security/advisories/mfsa2026-97/
  • https://www.mozilla.org/en-US/security/advisories/mfsa2026-98/
  • https://www.mozilla.org/en-US/security/advisories/mfsa2026-99/
  • https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-92035
  • https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-96869
  • https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-100756 (to CVE-2026-100826)
  • https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-100828 (to CVE-2026-100832)


Tag: Firefox , Mozilla
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