Description
JIT optimizations involving the Javascript arguments object could confuse later optimizations. This risk was already mitigated by various precautions in the code, resulting in this bug rated at only moderate severity. This vulnerability affects Firefox ESR < 78.1, Firefox < 79, and Thunderbird < 78.1.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Firefox ESR | unspecified – < 78.1 | 78.1 |
| Mozilla | Firefox | unspecified – < 79 | 79 |
| Mozilla | Thunderbird | unspecified – < 78.1 | 78.1 |
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 | 79.0+build1-0ubuntu0.20.04.1 | USN-4443-1 |
| 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 | 79.0+build1-0ubuntu0.18.04.1 | USN-4443-1 |
| 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 | 79.0+build1-0ubuntu0.16.04.2 | USN-4443-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | firefox | 78.2.0-2.el8_2 | RHSA-2020:3557 |
| RHEL 7 | firefox | 78.3.0-1.el7_9 | RHSA-2020:4080 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8.1 EUS | firefox | 78.2.0-3.el8_1 | RHSA-2020:3559 |
| RHEL 8.0 E4S | firefox | 78.2.0-3.el8_0 | RHSA-2020:3555 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP2 | MozillaFirefox | 78.1.0-8.3.1 | SUSE-SU-2020:2147-1 |
| SLES 15 SP2 | MozillaFirefox-branding-SLE | 78-9.2.4 | SUSE-SU-2020:2147-1 |
| SLES 15 SP2 | pipewire | 0.3.6-3.3.2 | SUSE-SU-2020:2147-1 |
| SLES 15 SP1 | MozillaFirefox | 78.1.0-3.100.2 | SUSE-SU-2020:2118-1 |
| SLES 12 SP5 | MozillaFirefox | 78.1.0-112.8.1 | SUSE-SU-2020:2100-1 |
| SLES 12 SP4 | MozillaFirefox | 78.1.0-112.8.1 | SUSE-SU-2020:2100-1 |
| SLES 12 SP3 | MozillaFirefox | 78.1.0-112.8.1 | SUSE-SU-2020:2100-1 |
Show 13 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP2 | MozillaFirefox | 78.1.0-112.8.1 | SUSE-SU-2020:2100-1 |
| SLES 11 SP4 | MozillaFirefox | 78.1.0-78.87.1 | SUSE-SU-2020:14456-1 |
| SLES for SAP 12 SP5 | MozillaFirefox | 78.1.0-112.8.1 | SUSE-SU-2020:2100-1 |
| SLES for SAP 12 SP4 | MozillaFirefox | 78.1.0-112.8.1 | SUSE-SU-2020:2100-1 |
| SLES for SAP 12 SP3 | MozillaFirefox | 78.1.0-112.8.1 | SUSE-SU-2020:2100-1 |
| SLES for SAP 12 SP2 | MozillaFirefox | 78.1.0-112.8.1 | SUSE-SU-2020:2100-1 |
| SUSE OpenStack Cloud Crowbar 9 | MozillaFirefox | 78.1.0-112.8.1 | SUSE-SU-2020:2100-1 |
| SUSE OpenStack Cloud Crowbar 8 | MozillaFirefox | 78.1.0-112.8.1 | SUSE-SU-2020:2100-1 |
| SUSE OpenStack Cloud 9 | MozillaFirefox | 78.1.0-112.8.1 | SUSE-SU-2020:2100-1 |
| SUSE OpenStack Cloud 8 | MozillaFirefox | 78.1.0-112.8.1 | SUSE-SU-2020:2100-1 |
| SUSE OpenStack Cloud 7 | MozillaFirefox | 78.1.0-112.8.1 | SUSE-SU-2020:2100-1 |
| SUSE HPE Helion OpenStack 8 | MozillaFirefox | 78.1.0-112.8.1 | SUSE-SU-2020:2100-1 |
| SUSE Enterprise Storage 5 | MozillaFirefox | 78.1.0-112.8.1 | SUSE-SU-2020:2100-1 |
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 | 78.1.0-lp152.2.12.1 | openSUSE-SU-2020:1189-1, openSUSE-SU-2020:1155-1 |
| openSUSE Leap 15.2 | pipewire | 0.3.6-lp152.2.3.1 | openSUSE-SU-2020:1189-1 |
| openSUSE Leap 15.1 | MozillaFirefox | 78.1.0-lp151.2.61.1 | openSUSE-SU-2020:1147-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | librewolf | 79.0-r0 | — |
| Alpine v3.23 | firefox +1 | 79.0-r0 | — |
| Alpine v3.23 | firefox-esr | 78.1.0-r0 | — |
| Alpine v3.22 | firefox +1 | 79.0-r0 | — |
| Alpine v3.22 | firefox-esr | 78.1.0-r0 | — |
| Alpine v3.21 | firefox +1 | 79.0-r0 | — |
| Alpine v3.21 | firefox-esr | 78.1.0-r0 | — |
| Alpine v3.20 | firefox | 79.0-r0 | — |
| Alpine v3.20 | firefox-esr | 78.1.0-r0 | — |
Show 8 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | firefox | 79.0-r0 | — |
| Alpine v3.19 | firefox-esr | 78.1.0-r0 | — |
| Alpine v3.18 | firefox | 79.0-r0 | — |
| Alpine v3.18 | firefox-esr | 78.1.0-r0 | — |
| Alpine v3.17 | firefox | 79.0-r0 | — |
| Alpine v3.17 | firefox-esr | 78.1.0-r0 | — |
| Alpine v3.16 | firefox | 79.0-r0 | — |
| Alpine v3.16 | firefox-esr | 78.1.0-r0 | — |
| Alpine v3.15 | firefox | 79.0-r0 | — |
| Alpine v3.15 | firefox-esr | 78.1.0-r0 | — |
| Alpine v3.14 | firefox | 79.0-r0 | — |
| Alpine v3.14 | firefox-esr | 78.1.0-r0 | — |
| Alpine v3.13 | firefox | 79.0-r0 | — |
| Alpine v3.13 | firefox-esr | 78.1.0-r0 | — |
| Alpine v3.12 | firefox | 79.0-r0 | — |
| Alpine v3.12 | firefox-esr | 78.1.0-r0 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | firefox | 78.2.0-2.0.1.el8_2 | ELSA-2020-3557 |
| Oracle Linux 7 | firefox | 78.3.0-1.0.1.el7_9 | ELSA-2020-4080 |
Advisories 16
- RHSA-2020:4080 Red Hat Security Advisory: firefox security and bug fix update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- USN-4443-1 firefox vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- SUSE-SU-2020:14456-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:1147-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:1155-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:2147-1 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
- SUSE-SU-2020:2118-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:1189-1 Security update for MozillaFirefox 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
- SUSE-SU-2020:2100-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- RHSA-2020:3557 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jan 28, 2026
- RHSA-2020:3555 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jan 14, 2026
- RHSA-2020:3559 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jan 14, 2026
- ELSA-2020-4080 Important: firefox security and bug fix update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Oct 13, 2020
- ELSA-2020-3557 Important: firefox security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Aug 28, 2020