CVE-2021-23971: Mozilla Firefox

Medium severity, CVSS 6.5. EPSS: 1% chance of exploitation in the next 30 days.

When processing a redirect with a conflicting Referrer-Policy, Firefox would have adopted the redirect's Referrer-Policy. This would have potentially resulted in more information than intended by the original origin being provided to the destination of the redirect. This vulnerability affects Firefox < 86.

Affected products

• Mozilla Firefox: before 86.0 (fixed in 86.0)

Published 2021-02-26. Last modified 2026-06-17.