CVE-2026-4721
Memory Corruption in Firefox and Thunderbird Enables Code Execution
Publication date: 2026-03-24
Last updated on: 2026-04-13
Assigner: Mozilla Corporation
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| mozilla | firefox | to 149.0 (exc) |
| mozilla | firefox | to 115.34.0 (exc) |
| mozilla | firefox | From 128.0 (inc) to 140.9.0 (exc) |
| mozilla | thunderbird | to 149.0 (exc) |
| mozilla | thunderbird | to 140.9.0 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-120 | The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability involves memory safety bugs found in specific versions of Firefox and Thunderbird, including Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird ESR 140.8, Firefox 148, and Thunderbird 148.
Some of these bugs showed evidence of memory corruption, which means that the software's memory could be improperly accessed or modified.
It is presumed that with enough effort, some of these bugs could be exploited to run arbitrary code, potentially allowing an attacker to execute malicious actions on the affected system.
How can this vulnerability impact me? :
The impact of this vulnerability could be severe because exploitation might allow an attacker to run arbitrary code on your system.
This could lead to unauthorized access, data theft, system compromise, or other malicious activities depending on the attacker's intent and the environment in which the software is used.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
I don't know
What immediate steps should I take to mitigate this vulnerability?
I don't know