CVE-2023-5722: Mozilla Firefox

Medium severity, CVSS 5.3. EPSS: 0.6% chance of exploitation in the next 30 days.

Using iterative requests an attacker was able to learn the size of an opaque response, as well as the contents of a server-supplied Vary header. 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.