CVE-2024-6611: Mozilla Firefox

Critical severity, CVSS 9.8. EPSS: 0.7% chance of exploitation in the next 30 days.

A nested iframe, triggering a cross-site navigation, could send SameSite=Strict or Lax cookies. This vulnerability affects Firefox < 128 and Thunderbird < 128.

Affected products

• Mozilla Firefox: before 128.0 (fixed in 128.0)
• Mozilla Thunderbird: before 128.0 (fixed in 128.0)

Published 2024-07-09. Last modified 2026-06-17.