Description
Mozilla developers and community members reported memory safety bugs present in Firefox 77. 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 < 78.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Firefox | unspecified – < 78 | 78 |
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.
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | firefox | 78.0.1+build1-0ubuntu0.20.04.1 | USN-4408-1 |
| Ubuntu 20.04 LTS | mozjs52 +1 | No fix yet | — |
| Ubuntu 20.04 LTS | thunderbird | 1:78.7.1+build1-0ubuntu0.20.04.1 | — |
| Ubuntu 18.04 LTS | firefox | 78.0.1+build1-0ubuntu0.18.04.1 | USN-4408-1 |
| Ubuntu 18.04 LTS | mozjs38 +1 | No fix yet | — |
| Ubuntu 18.04 LTS | thunderbird | 1:78.8.1+build1-0ubuntu0.18.04.1 | — |
| Ubuntu 16.04 LTS | firefox | 78.0.1+build1-0ubuntu0.16.04.1 | USN-4408-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP2 | MozillaFirefox | 78.0.1-3.94.2 | SUSE-SU-2020:1898-1 |
| SLES 15 SP2 | MozillaFirefox-branding-SLE | 78-4.14.1 | SUSE-SU-2020:1898-1 |
| SLES 15 SP1 | MozillaFirefox | 78.0.1-3.94.2 | SUSE-SU-2020:1898-1 |
| SLES 15 SP1 | MozillaFirefox-branding-SLE | 78-4.14.1 | SUSE-SU-2020:1898-1 |
| SLES 12 SP5 | MozillaFirefox | 78.0.1-112.3.1 | SUSE-SU-2020:1899-1 |
| SLES 12 SP5 | MozillaFirefox-branding-SLE | 78-35.3.1 | SUSE-SU-2020:1899-1 |
| SLES 12 SP4 | MozillaFirefox | 78.0.1-112.3.1 | SUSE-SU-2020:1899-1 |
| SLES 12 SP4 | MozillaFirefox-branding-SLE | 78-35.3.1 | SUSE-SU-2020:1899-1 |
| SLES 12 SP3 | MozillaFirefox | 78.0.1-112.3.1 | SUSE-SU-2020:1899-1 |
| SLES 12 SP3 | MozillaFirefox-branding-SLE | 78-35.3.1 | SUSE-SU-2020:1899-1 |
Show 13 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP2 | MozillaFirefox | 78.0.1-112.3.1 | SUSE-SU-2020:1899-1 |
| SLES 12 SP2 | MozillaFirefox-branding-SLE | 78-35.3.1 | SUSE-SU-2020:1899-1 |
| SLES 11 SP4 | MozillaFirefox | 78.0.1-78.80.2 | SUSE-SU-2020:14421-1 |
| SLES 11 SP4 | MozillaFirefox-branding-SLED | 78-21.12.1 | SUSE-SU-2020:14421-1 |
| SLES for SAP 12 SP5 | MozillaFirefox | 78.0.1-112.3.1 | SUSE-SU-2020:1899-1 |
| SLES for SAP 12 SP5 | MozillaFirefox-branding-SLE | 78-35.3.1 | SUSE-SU-2020:1899-1 |
| SLES for SAP 12 SP4 | MozillaFirefox | 78.0.1-112.3.1 | SUSE-SU-2020:1899-1 |
| SLES for SAP 12 SP4 | MozillaFirefox-branding-SLE | 78-35.3.1 | SUSE-SU-2020:1899-1 |
| SLES for SAP 12 SP3 | MozillaFirefox | 78.0.1-112.3.1 | SUSE-SU-2020:1899-1 |
| SLES for SAP 12 SP3 | MozillaFirefox-branding-SLE | 78-35.3.1 | SUSE-SU-2020:1899-1 |
| SLES for SAP 12 SP2 | MozillaFirefox | 78.0.1-112.3.1 | SUSE-SU-2020:1899-1 |
| SLES for SAP 12 SP2 | MozillaFirefox-branding-SLE | 78-35.3.1 | SUSE-SU-2020:1899-1 |
| SUSE OpenStack Cloud Crowbar 9 | MozillaFirefox | 78.0.1-112.3.1 | SUSE-SU-2020:1899-1 |
| SUSE OpenStack Cloud Crowbar 9 | MozillaFirefox-branding-SLE | 78-35.3.1 | SUSE-SU-2020:1899-1 |
| SUSE OpenStack Cloud Crowbar 8 | MozillaFirefox | 78.0.1-112.3.1 | SUSE-SU-2020:1899-1 |
| SUSE OpenStack Cloud Crowbar 8 | MozillaFirefox-branding-SLE | 78-35.3.1 | SUSE-SU-2020:1899-1 |
| SUSE OpenStack Cloud 9 | MozillaFirefox | 78.0.1-112.3.1 | SUSE-SU-2020:1899-1 |
| SUSE OpenStack Cloud 9 | MozillaFirefox-branding-SLE | 78-35.3.1 | SUSE-SU-2020:1899-1 |
| SUSE OpenStack Cloud 8 | MozillaFirefox | 78.0.1-112.3.1 | SUSE-SU-2020:1899-1 |
| SUSE OpenStack Cloud 8 | MozillaFirefox-branding-SLE | 78-35.3.1 | SUSE-SU-2020:1899-1 |
| SUSE OpenStack Cloud 7 | MozillaFirefox | 78.0.1-112.3.1 | SUSE-SU-2020:1899-1 |
| SUSE OpenStack Cloud 7 | MozillaFirefox-branding-SLE | 78-35.3.1 | SUSE-SU-2020:1899-1 |
| SUSE HPE Helion OpenStack 8 | MozillaFirefox | 78.0.1-112.3.1 | SUSE-SU-2020:1899-1 |
| SUSE HPE Helion OpenStack 8 | MozillaFirefox-branding-SLE | 78-35.3.1 | SUSE-SU-2020:1899-1 |
| SUSE Enterprise Storage 5 | MozillaFirefox | 78.0.1-112.3.1 | SUSE-SU-2020:1899-1 |
| SUSE Enterprise Storage 5 | MozillaFirefox-branding-SLE | 78-35.3.1 | SUSE-SU-2020:1899-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaFirefox | 92.0-1.2 | openSUSE-SU-2024:10600-1 |
| openSUSE Tumbleweed | firefox-esr | 128.5.1-1.1 | openSUSE-SU-2024:14572-1 |
| openSUSE Leap 15.2 | MozillaFirefox | 78.0.1-lp152.2.5.1 | openSUSE-SU-2020:0983-1 |
| openSUSE Leap 15.1 | MozillaFirefox | 78.0.1-lp151.2.53.1 | openSUSE-SU-2020:1017-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | librewolf | 78.0-r0 | — |
| Alpine v3.23 | firefox +1 | 78.0-r0 | — |
| Alpine v3.22 | firefox +1 | 78.0-r0 | — |
| Alpine v3.21 | firefox +1 | 78.0-r0 | — |
| Alpine v3.20 | firefox | 78.0-r0 | — |
Show 8 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | firefox | 78.0-r0 | — |
| Alpine v3.18 | firefox | 78.0-r0 | — |
| Alpine v3.17 | firefox | 78.0-r0 | — |
| Alpine v3.16 | firefox | 78.0-r0 | — |
| Alpine v3.15 | firefox | 78.0-r0 | — |
| Alpine v3.14 | firefox | 78.0-r0 | — |
| Alpine v3.13 | firefox | 78.0-r0 | — |
| Alpine v3.12 | firefox | 78.0-r0 | — |
Advisories 9
- USN-4408-1 firefox vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- SUSE-SU-2020:1899-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:1017-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:14421-1 Security update for MozillaFirefox 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
- openSUSE-SU-2024:14572-1 firefox-esr-128.5.1-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:0983-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:1898-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2023-0457 Mozilla Firefox/Thunderbird: Mehrere Schwachstellen BSI CERT-Bund (WID) · May 1, 2025
References
- https://www.mozilla.org/security/advisories/mfsa2020-24/
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=1608068%2C1609951%2C1631187%2C1637682
- openSUSE-SU-2020:0983 vendor-advisory
- openSUSE-SU-2020:1017 vendor-advisory
- GLSA-202007-10 vendor-advisory