Memory Safety Vulnerabilities in Firefox and Thunderbird by Mozilla
CVE-2025-9184

8.1HIGH

Key Information:

Vendor

Mozilla
Status
Firefox
Firefox Esr
Thunderbird
Vendor
CVE Published:
19 August 2025

What is CVE-2025-9184?

Memory safety issues have been detected in Firefox and Thunderbird, particularly in versions prior to 142 and 140.2 respectively. These vulnerabilities manifest as memory corruption bugs, which could potentially be leveraged for arbitrary code execution if exploited. Users are urged to upgrade to the latest versions, as updates in Firefox ESR 140.2 and Thunderbird ESR 140.2 address these security flaws, mitigating risks associated with these vulnerabilities.

Affected Version(s)

Firefox < 142

Firefox ESR < 140.2

Thunderbird < 142

References

https://bugzilla.mozilla.org/buglist.cgi?bug_id=1929482%2...
https://www.mozilla.org/security/advisories/mfsa2025-64/
https://www.mozilla.org/security/advisories/mfsa2025-67/

CVSS V3.1

Score:
8.1
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Paul Bone, Ryan VanderMeulen and the Mozilla Fuzzing Team
.