Description
A malicious webpage could have triggered a use-after-free, memory corruption, and a potentially exploitable crash. *This bug could only be triggered when accessibility was enabled.*. This vulnerability affects Thunderbird < 78.12, Firefox ESR < 78.12, and Firefox < 90.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Thunderbird | unspecified – < 78.12 | 78.12 |
| Mozilla | Firefox ESR | unspecified – < 78.12 | 78.12 |
| Mozilla | Firefox | unspecified – < 90 | 90 |
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 | 78.12.0esr-1 | — |
| Debian 14 | thunderbird | 1:78.12.0-1 | — |
| Debian 13 | firefox-esr | 78.12.0esr-1 | — |
| Debian 13 | thunderbird | 1:78.12.0-1 | — |
| Debian 12 | firefox-esr | 78.12.0esr-1 | — |
| Debian 12 | thunderbird | 1:78.12.0-1 | — |
| Debian 10 | firefox-esr | 78.12.0esr-1~deb10u1 | DSA-4939-1 |
| Debian 10 | thunderbird | 1:78.12.0-1~deb10u1 | DSA-4940-1 |
| Debian 9 | firefox-esr | 78.12.0esr-1~deb9u1 | DLA-2709-1 |
| Debian 9 | thunderbird | 1:78.12.0-1~deb9u1 | DLA-2711-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 22.04 LTS | mozjs78 | No fix yet | — |
| Ubuntu 20.04 LTS | firefox | 90.0+build1-0ubuntu0.20.04.1 | USN-5011-1 |
| Ubuntu 20.04 LTS | mozjs52 +1 | No fix yet | — |
| Ubuntu 20.04 LTS | thunderbird | 1:78.13.0+build1-0ubuntu0.20.04.2 | USN-5058-1 |
| Ubuntu 18.04 LTS | firefox | 90.0+build1-0ubuntu0.18.04.1 | USN-5011-1 |
| Ubuntu 18.04 LTS | mozjs38 +1 | No fix yet | — |
| Ubuntu 18.04 LTS | thunderbird | 1:78.13.0+build1-0ubuntu0.18.04.1 | USN-5058-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | firefox | 78.12.0-1.el8_4 | RHSA-2021:2743 |
| RHEL 8 | thunderbird | 78.12.0-3.el8_4 | RHSA-2021:2883 |
| RHEL 7 | firefox | 78.12.0-1.el7_9 | RHSA-2021:2741 |
| RHEL 7 | thunderbird | 78.12.0-2.el7_9 | RHSA-2021:2881 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8.2 EUS | firefox | 78.12.0-1.el8_2 | RHSA-2021:2742 |
| RHEL 8.2 EUS | thunderbird | 78.12.0-2.el8_2 | RHSA-2021:2914 |
| RHEL 8.1 EUS | firefox | 78.12.0-1.el8_1 | RHSA-2021:2740 |
| RHEL 8.1 EUS | thunderbird | 78.12.0-2.el8_1 | RHSA-2021:2882 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 8 | firefox | 78.12.0-1.el8_4 | RLSA-2021:2743 |
| Rocky Linux 8 | thunderbird | 78.12.0-3.el8_4 | RLSA-2021:2883 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP3 | MozillaFirefox | 78.12.0-8.46.1 | SUSE-SU-2021:2393-1 |
| SLES 15 SP3 | MozillaThunderbird | 78.12.0-8.33.1 | SUSE-SU-2021:2458-1 |
| SLES 15 SP2 | MozillaFirefox | 78.12.0-8.46.1 | SUSE-SU-2021:2393-1 |
| SLES 15 SP2 | MozillaThunderbird | 78.12.0-8.33.1 | SUSE-SU-2021:2458-1 |
| SLES 15 SP1 | MozillaFirefox | 78.12.0-3.147.1 | SUSE-SU-2021:2478-1 |
| SLES 15 | MozillaFirefox | 78.12.0-3.147.1 | SUSE-SU-2021:2478-1 |
| SLES 12 SP5 | MozillaFirefox | 78.12.0-112.65.1 | SUSE-SU-2021:2389-1 |
Show 20 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP4 | MozillaFirefox | 78.12.0-112.65.1 | SUSE-SU-2021:2389-1 |
| SLES 12 SP3 | MozillaFirefox | 78.12.0-112.65.1 | SUSE-SU-2021:2389-1 |
| SLES 12 SP2 | MozillaFirefox | 78.12.0-112.65.1 | SUSE-SU-2021:2389-1 |
| SLES 11 SP4 | MozillaFirefox | 78.12.0-78.134.1 | SUSE-SU-2021:14766-1 |
| SLES for SAP 15 SP1 | MozillaFirefox | 78.12.0-3.147.1 | SUSE-SU-2021:2478-1 |
| SLES for SAP 15 | MozillaFirefox | 78.12.0-3.147.1 | SUSE-SU-2021:2478-1 |
| SLES for SAP 12 SP5 | MozillaFirefox | 78.12.0-112.65.1 | SUSE-SU-2021:2389-1 |
| SLES for SAP 12 SP4 | MozillaFirefox | 78.12.0-112.65.1 | SUSE-SU-2021:2389-1 |
| SLES for SAP 12 SP3 | MozillaFirefox | 78.12.0-112.65.1 | SUSE-SU-2021:2389-1 |
| SLE HPC 15 SP1 | MozillaFirefox | 78.12.0-3.147.1 | SUSE-SU-2021:2478-1 |
| SLE HPC 15 | MozillaFirefox | 78.12.0-3.147.1 | SUSE-SU-2021:2478-1 |
| SUSE OpenStack Cloud Crowbar 9 | MozillaFirefox | 78.12.0-112.65.1 | SUSE-SU-2021:2389-1 |
| SUSE OpenStack Cloud Crowbar 8 | MozillaFirefox | 78.12.0-112.65.1 | SUSE-SU-2021:2389-1 |
| SUSE OpenStack Cloud 9 | MozillaFirefox | 78.12.0-112.65.1 | SUSE-SU-2021:2389-1 |
| SUSE OpenStack Cloud 8 | MozillaFirefox | 78.12.0-112.65.1 | SUSE-SU-2021:2389-1 |
| SUSE Manager Server 4.0 | MozillaFirefox | 78.12.0-3.147.1 | SUSE-SU-2021:2478-1 |
| SUSE Manager Retail Branch Server 4.0 | MozillaFirefox | 78.12.0-3.147.1 | SUSE-SU-2021:2478-1 |
| SUSE Manager Proxy 4.0 | MozillaFirefox | 78.12.0-3.147.1 | SUSE-SU-2021:2478-1 |
| SUSE HPE Helion OpenStack 8 | MozillaFirefox | 78.12.0-112.65.1 | SUSE-SU-2021:2389-1 |
| SUSE Enterprise Storage 6 | MozillaFirefox | 78.12.0-3.147.1 | SUSE-SU-2021:2478-1 |
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 |
| openSUSE Leap 15.3 | MozillaFirefox | 78.12.0-8.46.1 | openSUSE-SU-2021:2393-1 |
| openSUSE Leap 15.3 | MozillaThunderbird | 78.12.0-8.33.1 | openSUSE-SU-2021:2458-1 |
| openSUSE Leap 15.2 | MozillaFirefox | 78.12.0-lp152.2.61.1 | openSUSE-SU-2021:1066-1 |
| openSUSE Leap 15.2 | MozillaThunderbird | 78.12.0-lp152.2.48.2 | openSUSE-SU-2021:1091-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | librewolf | 90.0-r0 | — |
| Alpine v3.23 | firefox +1 | 90.0-r0 | — |
| Alpine v3.23 | firefox-esr | 78.12.0-r0 | — |
| Alpine v3.23 | thunderbird | 91.3.2-r0 | — |
| Alpine v3.22 | firefox +1 | 90.0-r0 | — |
| Alpine v3.22 | firefox-esr | 78.12.0-r0 | — |
| Alpine v3.22 | thunderbird | 91.3.2-r0 | — |
| Alpine v3.21 | firefox +1 | 90.0-r0 | — |
| Alpine v3.21 | firefox-esr | 78.12.0-r0 | — |
| Alpine v3.21 | thunderbird | 91.3.2-r0 | — |
| Alpine v3.20 | firefox | 90.0-r0 | — |
| Alpine v3.20 | firefox-esr | 78.12.0-r0 | — |
| Alpine v3.20 | thunderbird | 91.3.2-r0 | — |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | firefox | 90.0-r0 | — |
| Alpine v3.19 | firefox-esr | 78.12.0-r0 | — |
| Alpine v3.19 | thunderbird | 91.3.2-r0 | — |
| Alpine v3.18 | firefox | 90.0-r0 | — |
| Alpine v3.18 | firefox-esr | 78.12.0-r0 | — |
| Alpine v3.18 | thunderbird | 91.3.2-r0 | — |
| Alpine v3.17 | firefox | 90.0-r0 | — |
| Alpine v3.17 | firefox-esr | 78.12.0-r0 | — |
| Alpine v3.17 | thunderbird | 91.3.2-r0 | — |
| Alpine v3.16 | firefox | 90.0-r0 | — |
| Alpine v3.16 | firefox-esr | 78.12.0-r0 | — |
| Alpine v3.16 | thunderbird | 91.3.2-r0 | — |
| Alpine v3.15 | firefox | 90.0-r0 | — |
| Alpine v3.15 | firefox-esr | 78.12.0-r0 | — |
| Alpine v3.14 | firefox-esr | 78.12.0-r0 | — |
| Alpine v3.13 | firefox-esr | 78.12.0-r0 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | thunderbird | 78.13.0-1.amzn2.0.1 | ALAS2-2021-1709 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | firefox | 78.12.0-1.0.1.el8_4 | ELSA-2021-2743 |
| Oracle Linux 8 | thunderbird | 78.12.0-3.0.1.el8_4 | ELSA-2021-2883 |
| Oracle Linux 7 | firefox | 78.12.0-1.0.1.el7_9 | ELSA-2021-2741 |
| Oracle Linux 7 | thunderbird | 78.12.0-2.0.1.el7_9 | ELSA-2021-2881 |
Advisories 33
- RHSA-2021:2881 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2021:2741 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- USN-5058-1 thunderbird vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- USN-5011-1 firefox vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DSA-4940-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-4939-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2709-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2711-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- RLSA-2021:2743 Important: firefox security update Rocky Linux Security Advisories · Feb 5, 2026
- RLSA-2021:2883 Important: thunderbird security update Rocky Linux Security Advisories · Feb 4, 2026
- SUSE-SU-2021:2389-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:2458-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:2393-1 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-2021:14766-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:1066-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:2478-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:2393-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:1091-1 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-2021:2458-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- RHSA-2021:2914 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2021:2882 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2021:2883 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2021:2743 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2021:2742 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2021:2740 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- openSUSE-SU-2024:10601-1 MozillaThunderbird-91.1.1-1.1 on GA media SUSE / openSUSE Security Updates · May 7, 2025
- ALAS2-2021-1709 Important: thunderbird security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Sep 15, 2021
- ELSA-2021-2881 Important: thunderbird security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Jul 27, 2021
- ELSA-2021-2883 Important: thunderbird security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Jul 27, 2021
- ELSA-2021-2741 Important: firefox security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Jul 16, 2021
- ELSA-2021-2743 Important: firefox security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Jul 16, 2021