Memory safety bugs present in Firefox ESR 140.8, Thunderbird ESR 140.8, Firefox 148 and Thunderbird 148. 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 < 149, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
High
Complete denial of service
CVSS Vector v3.1
Weakness Type (CWE)
Vulnerable Products 4
| Configuration | From (including) | Up to (excluding) |
|---|---|---|
|
Mozilla Firefox
cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
|
— |
140.9.0
|
|
Mozilla Firefox
cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*
|
— |
149.0
|
|
Mozilla Thunderbird
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:*
|
— |
140.9.0
|
|
Mozilla Thunderbird
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:*
|
— |
149.0
|
References 5
https://bugzilla.mozilla.org/buglist.cgi?bug_id=2004652%2C2019372%2C2021922%2C2…
security@mozilla.org
https://www.mozilla.org/security/advisories/mfsa2026-20/
security@mozilla.org
https://www.mozilla.org/security/advisories/mfsa2026-22/
security@mozilla.org
https://www.mozilla.org/security/advisories/mfsa2026-23/
security@mozilla.org
https://www.mozilla.org/security/advisories/mfsa2026-24/
security@mozilla.org