Memory Safety Vulnerabilities in Firefox and Thunderbird Products
CVE-2026-6784

7.5HIGH

Key Information:

Vendor

Mozilla
Status
Firefox
Vendor
CVE Published:
21 April 2026

What is CVE-2026-6784?

Firefox 149 and Thunderbird 149 contain memory safety bugs that potentially allow for memory corruption. If exploited, these vulnerabilities could lead to unauthorized execution of arbitrary code. Mozilla addressed these issues in the subsequent releases of Firefox 150 and Thunderbird 150, highlighting the importance of regular software updates.

Affected Version(s)

Firefox 150

References

https://bugzilla.mozilla.org/buglist.cgi?bug_id=1536243%2...
https://www.mozilla.org/security/advisories/mfsa2026-30/

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
None
User Interaction:
Required
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Ben Visness, Brian Grinstead, Christian Holler, Dimi Lee, Jens Stutte, Jim Mathies, John Schanck, Jon Coppeard, Karl Tomlinson, Maurice Dauer, Nika Layzell, Randell Jesup, Tom Schuster and the Mozilla Fuzzing Team
.