Description
Memory safety bugs were reported in Firefox 49 and Firefox ESR 45.4. 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 < 45.5, Firefox ESR < 45.5, and Firefox < 50.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Thunderbird | unspecified – < 45.5 | 45.5 |
| Mozilla | Firefox ESR | unspecified – < 45.5 | 45.5 |
| Mozilla | Firefox | unspecified – < 50 | 50 |
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 | 45.5.0esr-1 | — |
| Debian 13 | firefox-esr | 45.5.0esr-1 | — |
| Debian 12 | firefox-esr | 45.5.0esr-1 | — |
| Debian 8 | firefox-esr | 45.5.0esr-1~deb8u1 | DSA-3716-1 |
| Debian 8 | icedove | 1:45.5.1-1~deb8u1 | DSA-3730-1 |
| Debian 7 | firefox-esr | 45.5.1esr-1~deb7u1 | DLA-730-1 |
| Debian 7 | icedove | 1:45.5.1-1~deb7u1 | DLA-752-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | firefox | 50.0+build2-0ubuntu0.16.04.2 | USN-3124-1 |
| Ubuntu 16.04 LTS | thunderbird | 1:45.5.1+build1-0ubuntu0.16.04.1 | USN-3141-1 |
| Ubuntu 14.04 LTS | firefox | 50.0+build2-0ubuntu0.14.04.2 | USN-3124-1 |
| Ubuntu 14.04 LTS | thunderbird | 1:45.5.1+build1-0ubuntu0.14.04.1 | USN-3141-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | firefox +1 | 45.5.0-1.el7_3 | RHSA-2016:2825, RHSA-2016:2780 |
| RHEL 6 | firefox +1 | 45.5.0-1.el6_8 | RHSA-2016:2825, RHSA-2016:2780 |
| RHEL 5 | firefox +1 | 45.5.0-1.el5_11 | RHSA-2016:2825, RHSA-2016:2780 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat Rhel Productivity 5 | thunderbird | 45.5.0-1.el5_11 | RHSA-2016:2825 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP2 | MozillaFirefox | 45.5.0esr-88.1 | SUSE-SU-2016:3014-1 |
| SLES 12 SP2 | mozilla-nss | 3.21.3-50.1 | SUSE-SU-2016:3014-1 |
| SLES 12 SP1 | MozillaFirefox | 45.5.0esr-88.1 | SUSE-SU-2016:3014-1 |
| SLES 12 SP1 | mozilla-nss | 3.21.3-50.1 | SUSE-SU-2016:3014-1 |
| SLES 12 | MozillaFirefox | 45.5.0esr-88.1 | SUSE-SU-2016:3014-1 |
| SLES 12 | mozilla-nss | 3.21.3-50.1 | SUSE-SU-2016:3014-1 |
| SLES 11 SP4 | MozillaFirefox | 45.5.1esr-59.1 | SUSE-SU-2016:3080-1 |
| SLES 11 SP4 | mozilla-nss | 3.21.3-39.1 | SUSE-SU-2016:3080-1 |
| SLES 11 SP3 | MozillaFirefox | 45.5.1esr-59.1 | SUSE-SU-2016:3080-1 |
| SLES 11 SP3 | mozilla-nss | 3.21.3-39.1 | SUSE-SU-2016:3080-1 |
Show 10 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 11 SP2 | MozillaFirefox | 45.5.1esr-63.1 | SUSE-SU-2016:3105-1 |
| SLES 11 SP2 | mozilla-nss | 3.21.3-30.1 | SUSE-SU-2016:3105-1 |
| SLES for SAP 12 SP2 | MozillaFirefox | 45.5.0esr-88.1 | SUSE-SU-2016:3014-1 |
| SLES for SAP 12 SP2 | mozilla-nss | 3.21.3-50.1 | SUSE-SU-2016:3014-1 |
| SLES for SAP 12 SP1 | MozillaFirefox | 45.5.0esr-88.1 | SUSE-SU-2016:3014-1 |
| SLES for SAP 12 SP1 | mozilla-nss | 3.21.3-50.1 | SUSE-SU-2016:3014-1 |
| SLES for SAP 12 | MozillaFirefox | 45.5.0esr-88.1 | SUSE-SU-2016:3014-1 |
| SLES for SAP 12 | mozilla-nss | 3.21.3-50.1 | SUSE-SU-2016:3014-1 |
| SLES for SAP 11 SP4 | MozillaFirefox | 45.5.1esr-59.1 | SUSE-SU-2016:3080-1 |
| SLES for SAP 11 SP4 | mozilla-nss | 3.21.3-39.1 | SUSE-SU-2016:3080-1 |
| SUSE Package Hub 12 | MozillaThunderbird | 45.5.1-17.1 | openSUSE-SU-2016:3019-1 |
| SUSE OpenStack Cloud 5 | MozillaFirefox | 45.5.1esr-59.1 | SUSE-SU-2016:3080-1 |
| SUSE OpenStack Cloud 5 | mozilla-nss | 3.21.3-39.1 | SUSE-SU-2016:3080-1 |
| SUSE Manager Proxy 2.1 | MozillaFirefox | 45.5.1esr-59.1 | SUSE-SU-2016:3080-1 |
| SUSE Manager Proxy 2.1 | mozilla-nss | 3.21.3-39.1 | SUSE-SU-2016:3080-1 |
| SUSE Manager 2.1 | MozillaFirefox | 45.5.1esr-59.1 | SUSE-SU-2016:3080-1 |
| SUSE Manager 2.1 | mozilla-nss | 3.21.3-39.1 | SUSE-SU-2016:3080-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | MozillaFirefox | 45.5.1esr-59.1 | SUSE-SU-2016:3080-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | mozilla-nss | 3.21.3-39.1 | SUSE-SU-2016:3080-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaFirefox | 50.1.0-1.1 | openSUSE-SU-2024:10071-1 |
| openSUSE Tumbleweed | MozillaThunderbird | 45.5.1-1.1 | openSUSE-SU-2024:10230-1 |
| openSUSE Tumbleweed | firefox-esr | 128.5.1-1.1 | openSUSE-SU-2024:14572-1 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | firefox +1 | 45.5.0-1.0.1.el7_3 | ELSA-2016-2825, ELSA-2016-2780 |
Advisories 17
- RHSA-2016:2825 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2016:2780 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- USN-3124-1 firefox vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- USN-3141-1 thunderbird vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DLA-752-1 icedove - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-730-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-3716-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-3730-1 icedove - security update Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2016:3019-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:10230-1 MozillaThunderbird-45.5.1-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2016:3014-1 Security update for MozillaFirefox, mozilla-nss SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2016:3080-1 Security update for MozillaFirefox, mozilla-nss SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2016:3105-1 Security update for MozillaFirefox, mozilla-nss 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-2024:10071-1 MozillaFirefox-50.1.0-1.1 on GA media SUSE / openSUSE Security Updates · May 7, 2025
- ELSA-2016-2825 Important: thunderbird security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Nov 29, 2016
- ELSA-2016-2780 Critical: firefox security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Nov 16, 2016
References
- DSA-3730 vendor-advisory
- RHSA-2016:2825 vendor-advisory
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=1309720%2C1297062%2C1303710%2C1018486%2C1292590%2C1301343%2C1301496%2C1308048%2C1308346%2C1299519%2C1286911%2C1298169
- 94335 vdb-entry
- 1037298 vdb-entry
- GLSA-201701-15 vendor-advisory
- https://www.mozilla.org/security/advisories/mfsa2016-93/
- RHSA-2016:2780 vendor-advisory
- https://www.mozilla.org/security/advisories/mfsa2016-89/
- https://www.mozilla.org/security/advisories/mfsa2016-90/