CVE-2025-1942criticalCWE-908

CVE-2025-1942: critical vulnerability in Mozilla Firefox

Disclosure of uninitialized memory when .toUpperCase() causes string to get longer

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28Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 9.8epss 0.5%
When String.toUpperCase() caused a string to get longer it was possible for uninitialized memory to be incorporated into the result string. This vulnerability was fixed in Firefox 136 and Thunderbird 136.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected products
Mozilla · FirefoxMozilla · Thunderbird
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