CVE-2025-11721

Memory safety bug present in Firefox 143 and Thunderbird 143. This bug showed evidence of memory corruption and we presume that with enough effort this could have been exploited to run arbitrary code. This vulnerability affects Firefox < 144 and Thunderbird < 144.

CVSS v3 9.8 CRITICAL

9.8^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://bugzilla.mozilla.org/show_bug.cgi?id=1986816	Issue Tracking Permissions Required
https://www.mozilla.org/security/advisories/mfsa2025-81/	Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-84/	Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:mozilla:firefox::::::::
	cpe:2.3:a:mozilla:thunderbird::::::::

History

15 Oct 2025, 18:08

Type	Values Removed	Values Added
CPE		cpe:2.3:a:mozilla:thunderbird:::::::: cpe:2.3:a:mozilla:firefox::::::::
References	~~() https://bugzilla.mozilla.org/show_bug.cgi?id=1986816 -~~	() https://bugzilla.mozilla.org/show_bug.cgi?id=1986816 - Issue Tracking, Permissions Required
References	~~() https://www.mozilla.org/security/advisories/mfsa2025-81/ -~~	() https://www.mozilla.org/security/advisories/mfsa2025-81/ - Vendor Advisory
References	~~() https://www.mozilla.org/security/advisories/mfsa2025-84/ -~~	() https://www.mozilla.org/security/advisories/mfsa2025-84/ - Vendor Advisory
First Time		Mozilla thunderbird Mozilla firefox Mozilla

15 Oct 2025, 14:15

Type	Values Removed	Values Added
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 9.8
CWE		CWE-119

14 Oct 2025, 13:15

Type	Values Removed	Values Added
New CVE

Information

Published : 2025-10-14 13:15

Updated : 2025-10-15 18:08

NVD link : CVE-2025-11721

Mitre link : CVE-2025-11721

CVE.ORG link : CVE-2025-11721

JSON object : View

Products Affected

mozilla

thunderbird
firefox

CWE

CWE-119

Improper Restriction of Operations within the Bounds of a Memory Buffer

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