CVE-2026-0891

Memory safety bugs present in Firefox ESR 140.6, Thunderbird ESR 140.6, Firefox 146 and Thunderbird 146. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 147, Firefox ESR < 140.7, Thunderbird < 147, and Thunderbird < 140.7.

CVSS v3 8.1 HIGH

8.1^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.2 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://bugzilla.mozilla.org/buglist.cgi?bug_id=1964722%2C2000981%2C2003100%2C2003278	Broken Link
https://www.mozilla.org/security/advisories/mfsa2026-01/	Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-03/	Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-04/	Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-05/	Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:mozilla:firefox:::::esr:::*
	cpe:2.3:a:mozilla:firefox:::::-:::*
	cpe:2.3:a:mozilla:thunderbird:::::esr:::*
	cpe:2.3:a:mozilla:thunderbird:::::-:::*

History

No history.

Information

Published : 2026-01-13 14:16

Updated : 2026-01-22 19:13

NVD link : CVE-2026-0891

Mitre link : CVE-2026-0891

CVE.ORG link : CVE-2026-0891

JSON object : View

Products Affected

mozilla

firefox
thunderbird

CWE

CWE-119

Improper Restriction of Operations within the Bounds of a Memory Buffer

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