CVE-2021-23971

high

Published — · Modified —

CVSS v3

—

CVSS v2

—

VIR risk

8.0

Description

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.

Predictions

Exploit likelihood

20%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2021-23971

vendor Authored 2026-05-27

Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2021-23971.html

OS impact

OS	Version	Status	Fixed in
arch		fixed	`86.0-1`
sles		affected
debian	sid	fixed	`86.0-1`

References

https://www.suse.com/security/cve/CVE-2021-23971.html
https://security-tracker.debian.org/tracker/CVE-2021-23971

Verify integrity in audit chain (admin only). AS-IS.