CVE-2026-12309
MediumCVSS 6.5Exploitation Probability (EPSS)
Low risk14th percentile - higher than 14% of all known CVEs
Summary
A memory safety bug was fixed in Firefox 152 and Thunderbird 152. This vulnerability also affects Firefox ESR 140.12 and Thunderbird 140.12.
Risk Assessment
Exploitation of this vulnerability could lead to unauthorized memory access, posing risks to user data and application integrity.
Recommendation
It is recommended to update to the latest version of Firefox or Thunderbird to mitigate this vulnerability.
Other vulnerabilities in Firefox, Thunderbird
See all- CVE-2026-109781Medium
Denial-of-service in the Printing: Output component. This vulnerability was fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.
- CVE-2026-109779Medium
Race condition in the Networking: DNS component. This vulnerability was fixed in Firefox 158 and Thunderbird 158.
- CVE-2026-16408Critical
Integer overflow in the Audio/Video: Playback component in Firefox and Thunderbird. Fixed in versions 153.
- CVE-2026-16395Critical
Integer overflow in the Audio/Video component in Firefox and Thunderbird. Fixed in versions 153.
- CVE-2026-4729Critical
Memory safety bugs were found in Firefox 148 and Thunderbird 148. Some of these bugs showed evidence of memory corruption, which could potentially allow arbitrary code execution. The vulnerabilities were fixed in Firefox 149 and Thunderbird 149.
- CVE-2026-4720Critical
Memory safety bugs were found in Firefox ESR 140.8, Thunderbird ESR 140.8, Firefox 148 and Thunderbird 148. Some of these bugs showed evidence of memory corruption and could potentially be exploited to run arbitrary code with enough effort.
- CVE-2026-2807Critical
Memory safety bugs were found in Firefox 147 and Thunderbird 147. Some of these bugs showed evidence of memory corruption and could potentially be exploited to run arbitrary code. The vulnerability was fixed in Firefox 148 and Thunderbird 148.
- CVE-2026-2792Critical
Memory safety bugs were found in Firefox ESR 140.7, Firefox 147, Thunderbird ESR 140.7, and Thunderbird 147. Some of these bugs showed evidence of memory corruption and could potentially be exploited to run arbitrary code with enough effort.
- CVE-2026-74978High
Clickjacking vulnerability in the Widget component in Firefox and Thunderbird. The issue was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.
- CVE-2026-74977High
Integer overflow in the Graphics component in Firefox and Thunderbird. The issue was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.
Original NVD description (English source)
Memory safety bug fixed in Firefox 152. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Thunderbird 152, and Thunderbird 140.12.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS