high 8.8

CVE-2020-12410 json

Mozilla developers reported memory safety bugs present in Firefox 76 and Firefox ESR 68.8.

published 2020-07-09 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-4722

cvss: 8.8; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 1.7%; EPSS 1.7% chance of exploitation in 30 days, percentile 77%
public exploits: 0; none known

Mozilla developers reported memory safety bugs present in Firefox 76 and Firefox ESR 68.8. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Thunderbird < 68.9.0, Firefox < 77, and Firefox ESR < 68.9.

Patch / fix

fixed in 3 distros 7

Mozilla Thunderbird 68.9.0
Mozilla Firefox 77
Mozilla Firefox ESR 68.9

debian ubuntu red hat suse opensuse alpine arch linux

firefox-esr Debian 14, Debian 13, Debian 12 68.9.0esr-1
thunderbird Debian 14, Debian 13, Debian 12 1:68.9.0-1

debian advisories DEBIAN-CVE-2020-12410

firefox Ubuntu 16.04 LTS 77.0.1+build1-0ubuntu0.16.04.1
firefox Ubuntu 18.04 LTS 77.0.1+build1-0ubuntu0.18.04.1
firefox Ubuntu 20.04 LTS 77.0.1+build1-0ubuntu0.20.04.1
thunderbird Ubuntu 16.04 LTS 1:68.10.0+build1-0ubuntu0.16.04.1
thunderbird Ubuntu 18.04 LTS 1:68.10.0+build1-0ubuntu0.18.04.1
thunderbird Ubuntu 20.04 LTS 1:68.10.0+build1-0ubuntu0.20.04.1

ubuntu advisories UBUNTU-CVE-2020-12410

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

thunderbird RHEL 7 68.9.0-1.el7_8
thunderbird RHEL 8 68.9.0-1.el8_2
thunderbird RHEL 6 68.9.0-1.el6_10
firefox RHEL 7 68.9.0-1.el7_8
firefox RHEL 6 68.9.0-1.el6_10
firefox RHEL 8 68.9.0-1.el8_2
thunderbird RHEL 8.1 EUS 68.9.0-1.el8_1
thunderbird RHEL 8.0 E4S 68.9.0-1.el8_0

red hat advisories RHSA-2020:2611 RHSA-2020:2615 RHSA-2020:2614 RHSA-2020:2613 RHSA-2020:2616 RHSA-2020:2381

MozillaThunderbird SLE Workstation Extension 15 SP2, SLE Workstation Extension 15 SP1 68.9.0-3.85.2
MozillaFirefox SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +14 more 68.9.0-109.123.1
MozillaFirefox SLE Module for Desktop Applications 15 SP2, SLE Module for Desktop Applications 15 SP1 68.9.0-3.91.1
MozillaFirefox SLES 11 SP4-LTSS 68.9.0-78.77.1

suse advisories SUSE-SU-2020:1591-2 SUSE-SU-2020:1591-1 SUSE-SU-2020:1563-1 SUSE-SU-2020:1556-1 SUSE-SU-2020:14389-1

MozillaThunderbird openSUSE Tumbleweed 91.1.1-1.1
MozillaThunderbird openSUSE Leap 15.1 68.9.0-lp151.2.41.1
MozillaFirefox openSUSE Leap 15.1 68.9.0-lp151.2.48.1

opensuse advisories openSUSE-SU-2024:10601-1 openSUSE-SU-2020:0799-1 openSUSE-SU-2020:0789-1

mozjs68 Alpine 3.12 68.9.0-r0
firefox-esr Alpine 3.23, Alpine 3.22, Alpine 3.21 +10 more 68.9.0-r0
thunderbird Alpine 3.23, Alpine 3.22, Alpine 3.21 +5 more 68.9.0-r0

alpine advisories ALPINE-CVE-2020-12410

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

firefox Arch Linux 77.0-1
thunderbird Arch Linux 68.9.0-1

arch linux advisories AVG-1173 AVG-1179

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2020-12410 updated 2026-11-04 cvss 8.8

Mozilla: Memory safety bugs fixed in Firefox 77 and Firefox ESR 68.9

Red Hat Enterprise Linux 5 firefox, thunderbird
affected: no fix planned “Out of support scope”
Red Hat Enterprise Linux AppStream (v. 8) firefox 68.9.0-1.el8_2, thunderbird 68.9.0-1.el8_2
fixed: vendor fix RHSA-2020:2379
Red Hat Enterprise Linux AppStream E4S (v. 8.0) firefox 68.9.0-1.el8_0, thunderbird 68.9.0-1.el8_0
fixed: vendor fix RHSA-2020:2382
Red Hat Enterprise Linux AppStream EUS (v. 8.1) firefox 68.9.0-1.el8_1, thunderbird 68.9.0-1.el8_1
fixed: vendor fix RHSA-2020:2380
Red Hat Enterprise Linux Client (v. 7) firefox 68.9.0-1.el7_8, thunderbird 68.9.0-1.el7_8 Red Hat Enterprise Linux Client Optional (v. 7) firefox 68.9.0-1.el7_8
fixed: vendor fix RHSA-2020:2381
Red Hat Enterprise Linux Desktop (v. 6) firefox 68.9.0-1.el6_10, thunderbird 68.9.0-1.el6_10 Red Hat Enterprise Linux Desktop Optional (v. 6) firefox 68.9.0-1.el6_10 Red Hat Enterprise Linux HPC Node Optional (v. 6) firefox 68.9.0-1.el6_10 Red Hat Enterprise Linux Server (v. 6) firefox 68.9.0-1.el6_10
fixed: vendor fix RHSA-2020:2378
Red Hat Enterprise Linux Server (v. 7) firefox 68.9.0-1.el7_8
fixed: vendor fix RHSA-2020:2381
Red Hat Enterprise Linux Server Optional (v. 6) firefox 68.9.0-1.el6_10, thunderbird 68.9.0-1.el6_10
fixed: vendor fix RHSA-2020:2378

show 5 more

Red Hat Enterprise Linux Server Optional (v. 7) firefox 68.9.0-1.el7_8, thunderbird 68.9.0-1.el7_8
fixed: vendor fix RHSA-2020:2381
Red Hat Enterprise Linux Workstation (v. 6) firefox 68.9.0-1.el6_10, thunderbird 68.9.0-1.el6_10
fixed: vendor fix RHSA-2020:2378
Red Hat Enterprise Linux Workstation (v. 7) firefox 68.9.0-1.el7_8, thunderbird 68.9.0-1.el7_8
fixed: vendor fix RHSA-2020:2381
Red Hat Enterprise Linux Workstation Optional (v. 6) firefox 68.9.0-1.el6_10
fixed: vendor fix RHSA-2020:2378
Red Hat Enterprise Linux Workstation Optional (v. 7) firefox 68.9.0-1.el7_8
fixed: vendor fix RHSA-2020:2381

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.73% chance of exploitation in the next 30 days, higher than 77% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.1	8.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD	2.0	9.3	AV:N/AC:M/Au:N/C:C/I:C/A:C

Affected products

Mozilla Thunderbird
Mozilla Firefox
Mozilla Firefox ESR

Classification

Weakness

CWE-787 Out-of-bounds Write

References

usn.ubuntu.com /4421-1/
vendor-advisory, third-party-advisory
mozilla.org /security/advisories/mfsa2020-20/
vendor-advisory
mozilla.org /security/advisories/mfsa2020-21/
vendor-advisory
mozilla.org /security/advisories/mfsa2020-22/
vendor-advisory
bugzilla.mozilla.org /buglist.cgi?bug_id=1619305%2C1632717
issue-tracking, vendor-advisory

Sources

CVE List CVE-2020-12410
NVD CVE-2020-12410

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