CVE-2025-1942: Disclosure of uninitialized memory when .toUpperCase() causes string to get longer
Last updated 6 March 2025
Other sources
When String.toUpperCase() caused a string to get longer it was possible for uninitialized memory to be incorporated into the result string
— Mozilla
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Firefoxto a version that resolves this vulnerability.Fixed in 136 - Upgrade
Upgrade
Thunderbirdto a version that resolves this vulnerability.Fixed in 136 - Upgrade
Upgrade
debian/firefoxto a version that resolves this vulnerability.Fixed in 136.0.1-1
Event History
Peer vulnerabilities
Found alongside the following vulnerabilities.
Frequently Asked Questions
What is the severity of CVE-2025-1942?
The severity of CVE-2025-1942 is rated as high due to potential exposure of sensitive information from uninitialized memory.
How do I fix CVE-2025-1942?
To fix CVE-2025-1942, update Mozilla Firefox to version 136 or higher.
What are the implications of CVE-2025-1942?
The implications of CVE-2025-1942 include potential exposure of sensitive data and security risks associated with uninitialized memory.
What versions of Firefox are affected by CVE-2025-1942?
CVE-2025-1942 affects versions of Mozilla Firefox up to and including 136.
Can CVE-2025-1942 lead to code execution?
CVE-2025-1942 does not directly lead to code execution but may expose sensitive information that could be exploited.