CVE-2020-15659 json
Mozilla developers and community members reported memory safety bugs present in Firefox 78 and Firefox ESR 78.0.
published 2020-08-10 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-7646
- cvss
- 8.8
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 2.4%
- EPSS 2.4% chance of exploitation in 30 days, percentile 84%
- public exploits
- 0
- none known
Summary
Mozilla developers and community members reported memory safety bugs present in Firefox 78 and Firefox ESR 78.0. 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 Firefox < 79, Firefox ESR < 68.11, Firefox ESR < 78.1, Thunderbird < 68.11, and Thunderbird < 78.1.
Patch / fix
- Mozilla Firefox 79
- Mozilla Firefox ESR 68.11, 78.1
- Mozilla Thunderbird 68.11, 78.1
- firefox-esr Debian 14, Debian 13, Debian 12 68.11.0esr-1
- thunderbird Debian 14, Debian 13, Debian 12 1:68.11.0-1
debian advisories DEBIAN-CVE-2020-15659
- firefox Ubuntu 16.04 LTS 79.0+build1-0ubuntu0.16.04.2
- firefox Ubuntu 18.04 LTS 79.0+build1-0ubuntu0.18.04.1
- firefox Ubuntu 20.04 LTS 79.0+build1-0ubuntu0.20.04.1
- thunderbird Ubuntu 18.04 LTS 1:78.8.1+build1-0ubuntu0.18.04.1
- thunderbird Ubuntu 20.04 LTS 1:78.7.1+build1-0ubuntu0.20.04.1
ubuntu advisories UBUNTU-CVE-2020-15659
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 6 68.11.0-1.el6_10
- thunderbird RHEL 7 68.11.0-1.el7_8
- thunderbird RHEL 8 68.11.0-1.el8_2
- firefox RHEL 7 68.11.0-1.el7_8
- firefox RHEL 8 68.11.0-1.el8_2
- firefox RHEL 6 68.11.0-1.el6_10
- thunderbird RHEL 8.1 EUS 68.11.0-1.el8_1
- thunderbird RHEL 8.0 E4S 68.11.0-1.el8_0
red hat advisories RHSA-2020:3345RHSA-2020:3344RHSA-2020:3341RHSA-2020:3342RHSA-2020:3343RHSA-2020:3254
- MozillaThunderbird SLE Workstation Extension 15 SP2, SLE Workstation Extension 15 SP1 68.11.0-3.91.1
- MozillaFirefox SLE Module for Desktop Applications 15 SP2 78.1.0-8.3.1
- pipewire SLE Module for Desktop Applications 15 SP2 0.3.6-3.3.2
- MozillaFirefox-branding-SLE SLE Module for Desktop Applications 15 SP2 78-9.2.4
- MozillaFirefox SLE Module for Desktop Applications 15 SP1 78.1.0-3.100.2
- MozillaFirefox SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +15 more 78.1.0-112.8.1
- MozillaFirefox SLES 11 SP4-LTSS 78.1.0-78.87.1
suse advisories SUSE-SU-2020:14456-1SUSE-SU-2020:2179-1SUSE-SU-2020:2147-1SUSE-SU-2020:2118-1SUSE-SU-2020:2100-1
- firefox-esr openSUSE Tumbleweed 128.5.1-1.1
- MozillaFirefox openSUSE Tumbleweed 92.0-1.2
- MozillaThunderbird openSUSE Tumbleweed 91.1.1-1.1
- MozillaThunderbird openSUSE Leap 15.2 68.11.0-lp152.2.7.1
- MozillaFirefox openSUSE Leap 15.2 78.1.0-lp152.2.15.1
- pipewire openSUSE Leap 15.2 0.3.6-lp152.2.3.1
- MozillaThunderbird openSUSE Leap 15.1 68.11.0-lp151.2.47.1
- MozillaFirefox openSUSE Leap 15.2 78.1.0-lp152.2.12.1
opensuse advisories openSUSE-SU-2024:14572-1openSUSE-SU-2024:10600-1openSUSE-SU-2024:10601-1openSUSE-SU-2020:1205-1openSUSE-SU-2020:1189-1openSUSE-SU-2020:1179-1
- firefox Alpine 3.23, Alpine 3.22, Alpine 3.21 +9 more 79.0-r0
- mozjs68 Alpine 3.12 68.11.0-r0
- librewolf Alpine 3.24, Alpine 3.23, Alpine 3.22 +1 more 79.0-r0
- firefox-esr Alpine 3.11 68.11.0-r0
- firefox-esr Alpine 3.23, Alpine 3.22, Alpine 3.21 +9 more 78.1.0-r0
alpine advisories ALPINE-CVE-2020-15659
Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0
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-2020-15659 updated cvss 8.8
Mozilla: Memory safety bugs fixed in Firefox 79 and Firefox ESR 68.11
-
Red Hat Enterprise Linux 5 firefox, thunderbirdaffected: no fix planned “Out of support scope”
-
Red Hat Enterprise Linux AppStream (v. 8) firefox 68.11.0-1.el8_2, thunderbird 68.11.0-1.el8_2fixed: vendor fix RHSA-2020:3241
-
Red Hat Enterprise Linux AppStream E4S (v. 8.0) firefox 68.11.0-1.el8_0, thunderbird 68.11.0-1.el8_0fixed: vendor fix RHSA-2020:3229
-
Red Hat Enterprise Linux AppStream EUS (v. 8.1) firefox 68.11.0-1.el8_1, thunderbird 68.11.0-1.el8_1fixed: vendor fix RHSA-2020:3254
-
Red Hat Enterprise Linux Client (v. 7) firefox 68.11.0-1.el7_8, thunderbird 68.11.0-1.el7_8 Red Hat Enterprise Linux Client Optional (v. 7) firefox 68.11.0-1.el7_8fixed: vendor fix RHSA-2020:3253
-
Red Hat Enterprise Linux Desktop (v. 6) firefox 68.11.0-1.el6_10, thunderbird 68.11.0-1.el6_10 Red Hat Enterprise Linux Desktop Optional (v. 6) firefox 68.11.0-1.el6_10 Red Hat Enterprise Linux HPC Node Optional (v. 6) firefox 68.11.0-1.el6_10 Red Hat Enterprise Linux Server (v. 6) firefox 68.11.0-1.el6_10fixed: vendor fix RHSA-2020:3233
-
Red Hat Enterprise Linux Server (v. 7) firefox 68.11.0-1.el7_8fixed: vendor fix RHSA-2020:3253
-
Red Hat Enterprise Linux Server Optional (v. 6) firefox 68.11.0-1.el6_10, thunderbird 68.11.0-1.el6_10fixed: vendor fix RHSA-2020:3233
show 5 moreshow fewer
-
Red Hat Enterprise Linux Server Optional (v. 7) firefox 68.11.0-1.el7_8, thunderbird 68.11.0-1.el7_8fixed: vendor fix RHSA-2020:3253
-
Red Hat Enterprise Linux Workstation (v. 6) firefox 68.11.0-1.el6_10, thunderbird 68.11.0-1.el6_10fixed: vendor fix RHSA-2020:3233
-
Red Hat Enterprise Linux Workstation (v. 7) firefox 68.11.0-1.el7_8, thunderbird 68.11.0-1.el7_8fixed: vendor fix RHSA-2020:3253
-
Red Hat Enterprise Linux Workstation Optional (v. 6) firefox 68.11.0-1.el6_10fixed: vendor fix RHSA-2020:3233
-
Red Hat Enterprise Linux Workstation Optional (v. 7) firefox 68.11.0-1.el7_8fixed: vendor fix RHSA-2020:3253
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
2.39% chance of exploitation in the next 30 days, higher than 84% 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 Firefox
- Mozilla Firefox ESR
- Mozilla Thunderbird
Classification
- Weakness
-
- CWE-787 Out-of-bounds Write
References
-
lists.opensuse.org
/opensuse-security-announce/2020-08/msg00022.html
vendor-advisory, mailing-list, patch, third-party-advisory
-
lists.opensuse.org
/opensuse-security-announce/2020-08/msg00025.html
vendor-advisory, mailing-list, patch, third-party-advisory
-
lists.opensuse.org
/opensuse-security-announce/2020-08/msg00032.html
vendor-advisory, mailing-list, patch, third-party-advisory
-
usn.ubuntu.com
/4443-1/
vendor-advisory, patch, third-party-advisory
-
mozilla.org
/security/advisories/mfsa2020-30/
vendor-advisory
-
mozilla.org
/security/advisories/mfsa2020-35/
vendor-advisory
-
mozilla.org
/security/advisories/mfsa2020-32/
vendor-advisory
-
mozilla.org
/security/advisories/mfsa2020-33/
vendor-advisory
-
mozilla.org
/security/advisories/mfsa2020-31/
vendor-advisory
-
bugzilla.mozilla.org
/buglist.cgi?bug_id=1550133%2C1633880%2C1643613%2C1644839%2C1645835%2C1646006%2C1646787%2C1649347%2C1650811%2C
issue-tracking, permissions-required, vendor-advisory
Sources
- CVE List CVE-2020-15659
- NVD CVE-2020-15659
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.