Multiple vulnerabilities in Mozilla Firefox ESR

Description

Multiple vulnerabilities were found in Mozilla Firefox ESR. Malicious users can exploit these vulnerabilities to spoof user interface, bypass security restrictions, execute arbitrary code, cause denial of service, obtain sensitive information.

Below is a complete list of vulnerabilities:

1. Spoofing vulnerability in the Downloads Panel component can be exploited to spoof user interface.
2. Security vulnerability in DOM can be exploited to bypass security restrictions.
3. Memory safety vulnerability can be exploited to execute arbitrary code.
4. Use after free vulnerability in GC can be exploited to cause denial of service or execute arbitrary code.
5. Use after free vulnerability in JavaScript Engine can be exploited to cause denial of service or execute arbitrary code.
6. Information disclosure vulnerability in Networking for Windows can be exploited to obtain sensitive information.
7. Integer overflow vulnerability in Graphics can be exploited to cause denial of service.
8. Security UI vulnerability in Copy & Paste and Drag & Drop can be exploited to spoof user interface.
9. Use after free vulnerability in IPC can be exploited to cause denial of service or execute arbitrary code.

Original advisories

• MFSA2026-03

Related products

• Mozilla-Firefox-ESR

CVE list

• CVE-2025-14327
  critical
• CVE-2026-0877
  critical
• CVE-2026-0878
  critical
• CVE-2026-0879
  critical
• CVE-2026-0880
  critical
• CVE-2026-0882
  critical
• CVE-2026-0883
  high
• CVE-2026-0884
  critical
• CVE-2026-0885
  high
• CVE-2026-0886
  high
• CVE-2026-0887
  warning
• CVE-2026-0890
  high
• CVE-2026-0891
  critical

Read more

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