CVE-2024-1555: Mozilla Firefox

High severity, CVSS 8.3. EPSS: 0.5% chance of exploitation in the next 30 days.

When opening a website using the `firefox://` protocol handler, SameSite cookies were not properly respected. This vulnerability affects Firefox < 123.

Affected products

• Mozilla Firefox: before 123.0 (fixed in 123.0)

Published 2024-02-20. Last modified 2026-06-17.