CVE-2023-5723: Mozilla Firefox

Medium severity, CVSS 5.3. EPSS: 0.7% chance of exploitation in the next 30 days.

An attacker with temporary script access to a site could have set a cookie containing invalid characters using `document.cookie` that could have led to unknown errors. This vulnerability affects Firefox < 119.

Affected products

• Mozilla Firefox: before 119.0 (fixed in 119.0)

Published 2023-10-25. Last modified 2026-06-17.