CVE-2026-2779 is a security vulnerability in Mozilla Firefox's Networking: JAR component caused by incorrect boundary conditions. This flaw can potentially lead to memory safety issues. Mozilla addressed this vulnerability in Firefox 148 and Firefox ESR 140.8 as part of a comprehensive security update that fixed multiple critical and high-impact vulnerabilities across various components. The vulnerability is tracked under CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer). The vendor advisory confirms the fix availability and recommends updating to the patched versions.

The vulnerability could allow an attacker to cause memory corruption due to incorrect boundary checks in the Networking: JAR component, which may lead to security issues such as arbitrary code execution or sandbox escape. However, the vendor advisory rates the impact of this specific vulnerability as moderate. There are no known exploits in the wild at this time. The overall security update addresses numerous high-impact vulnerabilities, indicating a significant improvement in the product's security posture after patching.

Mozilla has released official fixes for this vulnerability in Firefox 148 and Firefox ESR 140.8. Users and administrators should update to these versions or later to remediate the issue. Since this is not a cloud service, remediation depends on applying the vendor's patches. No additional mitigation steps are indicated by the vendor advisory.