CVE-2025-1943: Memory safety bugs fixed in Firefox 136 and Thunderbird 136
Memory safety bugs present in Firefox 135 and Thunderbird 135. 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. This vulnerability was fixed in Firefox 136 and Thunderbird 136.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Thunderbirdto a version that resolves this vulnerability.Fixed in 136 - Upgrade
Upgrade
ubuntu/firefoxto a version that resolves this vulnerability.Fixed in 136.0+build3-0ubuntu0.20.04.1 - Upgrade
Upgrade
ubuntu/thunderbirdto a version that resolves this vulnerability.Fixed in 1:140.7.1+build1-0ubuntu0.22.04.1 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 136 - Upgrade
Upgrade
debian/firefoxto a version that resolves this vulnerability.Fixed in 159.0-1 - Upgrade
Upgrade
Firefoxto a version that resolves this vulnerability.Fixed in 136
Event History
Peer vulnerabilities
Found alongside the following vulnerabilities.
Frequently Asked Questions
What is the severity of CVE-2025-1943?
CVE-2025-1943 is considered to have high severity due to the potential for memory corruption and arbitrary code execution.
How do I fix CVE-2025-1943?
To fix CVE-2025-1943, users should update to Mozilla Firefox version 136 or higher.
Which software is affected by CVE-2025-1943?
CVE-2025-1943 affects Mozilla Firefox versions up to 135 and Mozilla Thunderbird.
Can CVE-2025-1943 lead to data breaches?
Yes, if exploited, CVE-2025-1943 could potentially lead to data breaches through arbitrary code execution.
Is CVE-2025-1943 being actively exploited?
As of the current information available, there is no confirmation that CVE-2025-1943 is actively being exploited in the wild.