CVE-2026-2795 Mozilla CVE debrief

Who should care

Organizations and individuals using Firefox and Thunderbird should prioritize updating their installations to the latest versions. This vulnerability has a high impact and can be exploited remotely. Security teams should review their inventory of Firefox and Thunderbird installations and ensure they are updated to version 148 or later.

Technical summary

CVE-2026-2795 is a use-after-free vulnerability in the JavaScript: GC component of Firefox and Thunderbird. This type of vulnerability occurs when a program attempts to access memory that has already been freed or deleted. An attacker could potentially exploit this vulnerability to execute arbitrary code or cause a denial-of-service condition. The vulnerability is rated as CRITICAL with a CVSS score of 9.8. Firefox and Thunderbird users should update to version 148 or later to mitigate this vulnerability.

Defensive priority

High priority should be given to updating Firefox and Thunderbird installations to version 148 or later. Security teams should review their inventory of installations and ensure they are updated. Compensating controls, such as monitoring for suspicious activity, may be necessary until updates can be applied.

Recommended defensive actions

• Update Firefox to version 148 or later
• Update Thunderbird to version 148 or later
• Review inventory of Firefox and Thunderbird installations
• Monitor for suspicious activity
• Apply vendor-provided advisories and patches

Evidence notes

The CVE record for CVE-2026-2795 was obtained from the official CVE website. The vulnerability details were obtained from the NVD database and Mozilla's security advisories. The CVSS score and severity were obtained from the NVD database. The vendor, Mozilla, has provided advisories for this vulnerability.

Official resources