What is CVE-2023-49060?

CVE-2023-49060 is a critical-severity vulnerability in Mozilla Firefox. CVSS score: 9.8/10. Published 2023-11-21.

How severe is CVE-2023-49060?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Vulnerability in Mozilla Firefox

CVE-2023-49060

An attacker could have accessed internal pages or data by ex-filtrating a security key from ReaderMode via the `referrerpolicy` attribute. This vulnerability affects Firefox for iOS < 120.

Published 2023-11-21 · last modified 2026-08-19.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.006 (49.7th percentile), scored 2026-10-20.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 50th percentile — 49.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Affected products

Mozilla Firefox
Mozilla Firefox For iOS — versions unspecified
Mozilla Firefox Mobile

References

bugzilla.mozilla.org/show_bug.cgi (Issue Tracking, Not Applicable)
www.mozilla.org/security/advisories/mfsa2023-51/ (Release Notes, Vendor Advisory)

Frequently asked questions

What is CVE-2023-49060?: CVE-2023-49060 is a critical-severity vulnerability in Mozilla Firefox. CVSS score: 9.8/10. Published 2023-11-21.
How severe is CVE-2023-49060?: Critical severity. CVSS v3 base score is 9.8 out of 10.