Firefox ESR 115.37/140.12: I18N Boundary Condition Flaw
CVE-2026-12330 Published on June 16, 2026

Incorrect boundary conditions in the Internationalization component
Incorrect boundary conditions in the Internationalization component. This vulnerability was fixed in Firefox ESR 140.12, Firefox ESR 115.37, and Thunderbird 140.12.

NVD

Vulnerability Analysis

CVE-2026-12330 is exploitable with network access, requires user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a small impact on confidentiality and integrity, and no impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
REQUIRED
Scope:
UNCHANGED
Confidentiality Impact:
LOW
Integrity Impact:
LOW
Availability Impact:
NONE

Weakness Type

What is a Buffer Overflow Vulnerability?

The software performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer.

CVE-2026-12330 has been classified to as a Buffer Overflow vulnerability or weakness.


Products Associated with CVE-2026-12330

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Affected Versions

Mozilla Firefox: Mozilla Thunderbird:

Exploit Probability

EPSS
0.16%
Percentile
5.96%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.