CVE-2023-34415: Mozilla Firefox

Medium severity, CVSS 6.1. EPSS: 0.4% chance of exploitation in the next 30 days.

When choosing a site-isolated process for a document loaded from a data: URL that was the result of a redirect, Firefox would load that document in the same process as the site that issued the redirect. This bypassed the site-isolation protections against Spectre-like attacks on sites that host an "open redirect". Firefox no longer follows HTTP redirects to data: URLs. This vulnerability affects Firefox < 114.

Affected products

• Mozilla Firefox: before 114.0 (fixed in 114.0)

Published 2023-06-19. Last modified 2026-06-17.