What is CVE-2020-12414?

CVE-2020-12414 is a medium-severity vulnerability in Mozilla Firefox, classified under Incomplete Cleanup. CVSS score: 6.5/10. Published 2020-07-09.

How severe is CVE-2020-12414?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Vulnerability in Mozilla Firefox

CVE-2020-12414

IndexedDB should be cleared when leaving private browsing mode and it is not, the API for WKWebViewConfiguration was being used incorrectly and requires the private instance of this object be deleted when leaving private mode. This vulnerability affects Firefox for iOS < 27.

Published 2020-07-09 · last modified 2026-08-19.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.007 (50.4th percentile), scored 2026-10-03.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 50th percentile — 50.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000

Affected products

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

Weakness classification (CWE)

CWE-459 — Incomplete Cleanup

References

www.mozilla.org/security/advisories/mfsa2020-23/ (Vendor Advisory)
bugzilla.mozilla.org/show_bug.cgi (Permissions Required, Issue Tracking, Vendor Advisory)

Frequently asked questions

What is CVE-2020-12414?: CVE-2020-12414 is a medium-severity vulnerability in Mozilla Firefox, classified under Incomplete Cleanup. CVSS score: 6.5/10. Published 2020-07-09.
How severe is CVE-2020-12414?: Medium severity. CVSS v3 base score is 6.5 out of 10.