CVE-2025-1942

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 v3 9.8 CRITICAL

9.8^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://bugzilla.mozilla.org/show_bug.cgi?id=1947139	Issue Tracking
https://www.mozilla.org/security/advisories/mfsa2025-14/	Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-17/	Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:mozilla:firefox::::::::
	cpe:2.3:a:mozilla:thunderbird::::::::

History

05 Oct 2026, 15:10

Type	Values Removed	Values Added
Summary	(es) Cuando String.toUpperCase() hacía que una cadena se hiciera más larga, era posible que la memoria no inicializada se incorporara a la cadena de resultado. Esta vulnerabilidad afecta a Firefox < 136 y Thunderbird < 136.	(es) Cuando String.toUpperCase() hacía que una cadena se hiciera más larga, era posible que la memoria no inicializada se incorporara a la cadena de resultado. Esta vulnerabilidad afecta a Firefox menor que 136 y Thunderbird menor que 136.

30 Sep 2026, 19:10

Type	Values Removed	Values Added
Summary	(es) Cuando String.toUpperCase() hacía que una cadena se hiciera más larga, era posible que la memoria no inicializada se incorporara a la cadena de resultado. Esta vulnerabilidad afecta a Firefox < 136 y Thunderbird < 136.	(es) Cuando String.toUpperCase() hacía que una cadena se hiciera más larga, era posible que la memoria no inicializada se incorporara a la cadena de resultado. Esta vulnerabilidad afecta a Firefox < 136 y Thunderbird < 136.

Information

Published : 2025-03-04 14:15

Updated : 2026-10-05 15:10

NVD link : CVE-2025-1942

Mitre link : CVE-2025-1942

CVE.ORG link : CVE-2025-1942

JSON object : View

Products Affected

mozilla

firefox
thunderbird

CWE

CWE-908

Use of Uninitialized Resource

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