CVE-2025-1020: Memory safety bugs fixed in Firefox 135 and Thunderbird 135
Last updated 11 February 2025
Other sources
Memory safety bugs present in Firefox 134 and Thunderbird 134. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code.
— Mozilla
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/firefoxto a version that resolves this vulnerability.Fixed in 135.0-1 - Upgrade
Upgrade
Firefoxto a version that resolves this vulnerability.Fixed in 135 - Upgrade
Upgrade
Thunderbirdto a version that resolves this vulnerability.Fixed in 135
Event History
Peer vulnerabilities
Found alongside the following vulnerabilities.
Frequently Asked Questions
What is the severity of CVE-2025-1020?
CVE-2025-1020 is considered a high-severity vulnerability due to the potential for arbitrary code execution.
How do I fix CVE-2025-1020?
To fix CVE-2025-1020, upgrade to Firefox or Thunderbird version 135 or later.
Which versions of Firefox are affected by CVE-2025-1020?
Firefox versions up to and including 134 are affected by CVE-2025-1020.
Which versions of Thunderbird are affected by CVE-2025-1020?
Thunderbird versions up to and including 134 are affected by CVE-2025-1020.
What types of vulnerabilities does CVE-2025-1020 include?
CVE-2025-1020 includes memory safety bugs that could potentially lead to memory corruption.