Description
Mozilla developers and community members reported memory safety bugs present in Firefox 63 and Firefox ESR 60.3. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code. This vulnerability affects Thunderbird < 60.4, Firefox ESR < 60.4, and Firefox < 64.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Thunderbird | unspecified – < 60.4 | 60.4 |
| Mozilla | Firefox ESR | unspecified – < 60.4 | 60.4 |
| Mozilla | Firefox | unspecified – < 64 | 64 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | firefox-esr | 60.4.0esr-1 | — |
| Debian 14 | thunderbird | 1:60.4.0-1 | — |
| Debian 13 | firefox-esr | 60.4.0esr-1 | — |
| Debian 13 | thunderbird | 1:60.4.0-1 | — |
| Debian 12 | firefox-esr | 60.4.0esr-1 | — |
| Debian 12 | thunderbird | 1:60.4.0-1 | — |
| Debian 9 | firefox-esr | 60.4.0esr-1~deb9u1 | DSA-4354-1 |
| Debian 9 | thunderbird | 1:60.4.0-1~deb9u1 | DSA-4362-1 |
| Debian 8 | firefox-esr | 60.4.0esr-1~deb8u1 | DLA-1605-1 |
| Debian 8 | thunderbird | 1:60.4.0-1~deb8u1 | DLA-1624-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | mozjs52 | No fix yet | — |
| Ubuntu 18.04 LTS | firefox | 64.0+build3-0ubuntu0.18.04.1 | USN-3844-1 |
| Ubuntu 18.04 LTS | mozjs38 +1 | No fix yet | — |
| Ubuntu 18.04 LTS | thunderbird | 1:60.4.0+build2-0ubuntu0.18.04.1 | USN-3868-1 |
| Ubuntu 16.04 LTS | firefox | 64.0+build3-0ubuntu0.16.04.1 | USN-3844-1 |
| Ubuntu 16.04 LTS | thunderbird | 1:60.4.0+build2-0ubuntu0.16.04.1 | USN-3868-1 |
| Ubuntu 14.04 LTS | firefox | 64.0+build3-0ubuntu0.14.04.1 | USN-3844-1 |
| Ubuntu 14.04 LTS | thunderbird | 1:60.4.0+build2-0ubuntu0.14.04.1 | USN-3868-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | firefox | 60.4.0-1.el7 | RHSA-2018:3833 |
| RHEL 7 | thunderbird | 60.4.0-1.el7_6 | RHSA-2019:0160 |
| RHEL 6 | firefox +1 | 60.4.0-1.el6 | RHSA-2019:0159, RHSA-2018:3831 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 | MozillaFirefox | 60.4.0-3.21.1 | SUSE-SU-2018:4235-1 |
| SLES 15 | MozillaThunderbird | 60.5.0-3.20.2 | SUSE-SU-2019:0338-1 |
| SLES 15 | mozilla-nspr | 4.20-3.3.2 | SUSE-SU-2018:4235-1 |
| SLES 15 | mozilla-nss | 3.40.1-3.7.2 | SUSE-SU-2018:4235-1 |
| SLES 12 SP4 | MozillaFirefox | 60.4.0esr-109.55.1 | SUSE-SU-2018:4236-1 |
| SLES 12 SP4 | mozilla-nspr | 4.20-19.6.1 | SUSE-SU-2018:4236-1 |
| SLES 12 SP4 | mozilla-nss | 3.40.1-58.18.1 | SUSE-SU-2018:4236-1 |
| SLES 12 SP3 | MozillaFirefox | 60.4.0esr-109.55.1 | SUSE-SU-2018:4236-1 |
| SLES 12 SP3 | mozilla-nspr | 4.20-19.6.1 | SUSE-SU-2018:4236-1 |
| SLES 12 SP3 | mozilla-nss | 3.40.1-58.18.1 | SUSE-SU-2018:4236-1 |
| SLES 12 SP2 | MozillaFirefox | 60.4.0esr-109.55.1 | SUSE-SU-2018:4236-1 |
| SLES 12 SP2 | mozilla-nspr | 4.20-19.6.1 | SUSE-SU-2018:4236-1 |
| SLES 12 SP2 | mozilla-nss | 3.40.1-58.18.1 | SUSE-SU-2018:4236-1 |
| SLES 12 SP1 | MozillaFirefox | 60.4.0esr-109.55.1 | SUSE-SU-2018:4236-1 |
| SLES 12 SP1 | mozilla-nspr | 4.20-19.6.1 | SUSE-SU-2018:4236-1 |
| SLES 12 SP1 | mozilla-nss | 3.40.1-58.18.1 | SUSE-SU-2018:4236-1 |
Show 8 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 | MozillaFirefox | 60.4.0esr-109.55.1 | SUSE-SU-2018:4236-1 |
| SLES 12 | mozilla-nspr | 4.20-19.6.1 | SUSE-SU-2018:4236-1 |
| SLES 12 | mozilla-nss | 3.40.1-58.18.1 | SUSE-SU-2018:4236-1 |
| SLES for SAP 12 SP4 | MozillaFirefox | 60.4.0esr-109.55.1 | SUSE-SU-2018:4236-1 |
| SLES for SAP 12 SP4 | mozilla-nspr | 4.20-19.6.1 | SUSE-SU-2018:4236-1 |
| SLES for SAP 12 SP4 | mozilla-nss | 3.40.1-58.18.1 | SUSE-SU-2018:4236-1 |
| SLES for SAP 12 SP3 | MozillaFirefox | 60.4.0esr-109.55.1 | SUSE-SU-2018:4236-1 |
| SLES for SAP 12 SP3 | mozilla-nspr | 4.20-19.6.1 | SUSE-SU-2018:4236-1 |
| SLES for SAP 12 SP3 | mozilla-nss | 3.40.1-58.18.1 | SUSE-SU-2018:4236-1 |
| SLES for SAP 12 SP2 | MozillaFirefox | 60.4.0esr-109.55.1 | SUSE-SU-2018:4236-1 |
| SLES for SAP 12 SP2 | mozilla-nspr | 4.20-19.6.1 | SUSE-SU-2018:4236-1 |
| SLES for SAP 12 SP2 | mozilla-nss | 3.40.1-58.18.1 | SUSE-SU-2018:4236-1 |
| SLES for SAP 12 SP1 | MozillaFirefox | 60.4.0esr-109.55.1 | SUSE-SU-2018:4236-2 |
| SLES for SAP 12 SP1 | mozilla-nspr | 4.20-19.6.1 | SUSE-SU-2018:4236-2 |
| SLES for SAP 12 SP1 | mozilla-nss | 3.40.1-58.18.1 | SUSE-SU-2018:4236-2 |
| SUSE Package Hub 12 | MozillaThunderbird | 60.5.1-79.1 | openSUSE-SU-2019:0249-1 |
| SUSE OpenStack Cloud 7 | MozillaFirefox | 60.4.0esr-109.55.1 | SUSE-SU-2018:4236-1 |
| SUSE OpenStack Cloud 7 | mozilla-nspr | 4.20-19.6.1 | SUSE-SU-2018:4236-1 |
| SUSE OpenStack Cloud 7 | mozilla-nss | 3.40.1-58.18.1 | SUSE-SU-2018:4236-1 |
| SUSE Enterprise Storage 4 | MozillaFirefox | 60.4.0esr-109.55.1 | SUSE-SU-2018:4236-1 |
| SUSE Enterprise Storage 4 | mozilla-nspr | 4.20-19.6.1 | SUSE-SU-2018:4236-1 |
| SUSE Enterprise Storage 4 | mozilla-nss | 3.40.1-58.18.1 | SUSE-SU-2018:4236-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaFirefox | 92.0-1.2 | openSUSE-SU-2024:10600-1 |
| openSUSE Tumbleweed | MozillaThunderbird | 91.1.1-1.1 | openSUSE-SU-2024:10601-1 |
| openSUSE Tumbleweed | firefox-esr | 128.5.1-1.1 | openSUSE-SU-2024:14572-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | thunderbird | 60.5.0-1.amzn2.0.1 | ALAS2-2019-1168 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | firefox | 60.4.0-1.0.1.el7 | ELSA-2018-3833 |
| Oracle Linux 7 | thunderbird | 60.4.0-1.0.1.el7_6 | ELSA-2019-0160 |
Advisories 21
- RHSA-2019:0160 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 29, 2026
- RHSA-2019:0159 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 29, 2026
- RHSA-2018:3833 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 29, 2026
- RHSA-2018:3831 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 29, 2026
- USN-3868-1 thunderbird vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- USN-3844-1 firefox vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DSA-4354-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-4362-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-1605-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-1624-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2018:4235-1 Security update for MozillaFirefox, mozilla-nspr and mozilla-nss SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:4236-1 Security update for MozillaFirefox, mozilla-nspr and mozilla-nss SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:10600-1 MozillaFirefox-92.0-1.2 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:4236-2 Security update for MozillaFirefox, mozilla-nspr and mozilla-nss SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2019:0338-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:14572-1 firefox-esr-128.5.1-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:10601-1 MozillaThunderbird-91.1.1-1.1 on GA media SUSE / openSUSE Security Updates · May 7, 2025
- openSUSE-SU-2019:0249-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · May 2, 2025
- ALAS2-2019-1168 Critical: thunderbird security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Mar 8, 2019
- ELSA-2019-0160 Important: thunderbird security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Jan 25, 2019
- ELSA-2018-3833 Critical: firefox security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Dec 18, 2018
References
- https://www.mozilla.org/security/advisories/mfsa2018-29/
- [debian-lts-announce] 20181213 [SECURITY] [DLA 1605-1] firefox-esr security update mailing-list
- RHSA-2018:3833 vendor-advisory
- RHSA-2018:3831 vendor-advisory
- DSA-4362 vendor-advisory
- GLSA-201903-04 vendor-advisory
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=1494752%2C1498765%2C1503326%2C1505181%2C1500759%2C1504365%2C1506640%2C1503082%2C1502013%2C1510471
- USN-3844-1 vendor-advisory
- 106168 vdb-entry
- RHSA-2019:0159 vendor-advisory
- https://www.mozilla.org/security/advisories/mfsa2018-31/
- https://www.mozilla.org/security/advisories/mfsa2018-30/
- DSA-4354 vendor-advisory
- USN-3868-1 vendor-advisory
- RHSA-2019:0160 vendor-advisory