A lock was missing when accessing a data structure and importing certificate information into the trust database.

published 2020-10-01 6 y ago modified 2026-08-19 2 mo ago also EUVD-2020-7655

cvss: 4.3; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.5%; EPSS 0.5% chance of exploitation in 30 days, percentile 45%
public exploits: 0; none known

A lock was missing when accessing a data structure and importing certificate information into the trust database. This vulnerability affects Firefox < 80 and Firefox for Android < 80.

Patch / fix

fixed in 2 distros 3

Mozilla Firefox 80
Mozilla Firefox for Android 80

ubuntu opensuse alpine

firefox Ubuntu 16.04 LTS 80.0+build2-0ubuntu0.16.04.1
firefox Ubuntu 18.04 LTS 80.0+build2-0ubuntu0.18.04.1
firefox Ubuntu 20.04 LTS 80.0+build2-0ubuntu0.20.04.1

ubuntu advisories UBUNTU-CVE-2020-15668

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

firefox-esr openSUSE Tumbleweed 128.5.1-1.1
MozillaFirefox openSUSE Tumbleweed 92.0-1.2

opensuse advisories openSUSE-SU-2024:14572-1 openSUSE-SU-2024:10600-1

firefox Alpine 3.23, Alpine 3.22, Alpine 3.21 +9 more 80.0-r0
librewolf Alpine 3.24, Alpine 3.23, Alpine 3.22 +1 more 80.0-r0

alpine advisories ALPINE-CVE-2020-15668

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Exploit prediction

0.54% chance of exploitation in the next 30 days, higher than 45% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.1	4.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
NVD	2.0	4.3	AV:N/AC:M/Au:N/C:P/I:N/A:N

Affected products

Mozilla Firefox
Mozilla Firefox for Android

Classification

Weakness

CWE-667 Improper Locking

References

mozilla.org /security/advisories/mfsa2020-39/
release-notes, vendor-advisory
mozilla.org /security/advisories/mfsa2020-36/
release-notes, vendor-advisory
bugzilla.mozilla.org /show_bug.cgi?id=1651520
issue-tracking, permissions-required, vendor-advisory

Sources

CVE List CVE-2020-15668
NVD CVE-2020-15668

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary