CVE-2026-4694
Published: 24 March 2026
Description
Incorrect boundary conditions, integer overflow in the Graphics component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
Mitigating Controls (NIST 800-53 r5)AI
Directly requires timely identification, reporting, and patching of software flaws like this integer overflow in Firefox and Thunderbird graphics component.
Enables ongoing vulnerability scanning to identify systems running affected versions of Firefox or Thunderbird vulnerable to this CVE.
Mandates obtaining and acting on vendor security advisories like Mozilla's MFSA to address this specific vulnerability through updates.
Security SummaryAI
CVE-2026-4694 is an integer overflow vulnerability stemming from incorrect boundary conditions in the Graphics component of Mozilla Firefox and Thunderbird. It affects versions of Firefox prior to 149, Firefox ESR prior to 115.34 and 140.9, and Thunderbird prior to 149 and 140.9. The issue is classified under CWE-190 (Integer Overflow or Wraparound) and CWE-754 (Improper Check for Unusual or Exceptional Conditions), with a CVSS v3.1 base score of 7.5.
The vulnerability enables remote attackers to exploit it over a network with low complexity, requiring no privileges, user interaction, or authentication. Successful exploitation results in high-impact denial of service, such as application crashes or resource exhaustion, without affecting confidentiality or integrity (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).
Mozilla's security advisories (MFSA 2026-20 through 2026-23) and the associated Bugzilla entry (bug 2018430) confirm the fix was implemented in the listed versions. Security practitioners should ensure affected systems are updated to Firefox 149 or later, Firefox ESR 115.34/140.9 or later, and Thunderbird 149/140.9 or later to mitigate the issue.
Details
- CWE(s)
Affected Products
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Integer overflow in browser graphics component enables remote exploitation causing application crash/resource exhaustion (CWE-190), directly matching T1499.004 Application or System Exploitation for Endpoint Denial of Service.