Description
Mozilla developers Andrew McCreight, Gabriele Svelto, Tom Ritter and the Mozilla Fuzzing Team reported memory safety bugs present in Firefox 99 and Firefox ESR 91.8. 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 Thunderbird < 91.9, Firefox ESR < 91.9, and Firefox < 100.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Thunderbird | unspecified – < 91.9 | 91.9 |
| Mozilla | Firefox ESR | unspecified – < 91.9 | 91.9 |
| Mozilla | Firefox | unspecified – < 100 | 100 |
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 | 91.9.0esr-1 | — |
| Debian 14 | thunderbird | 1:91.9.0-1 | — |
| Debian 13 | firefox-esr | 91.9.0esr-1 | — |
| Debian 13 | thunderbird | 1:91.9.0-1 | — |
| Debian 12 | firefox-esr | 91.9.0esr-1 | — |
| Debian 12 | thunderbird | 1:91.9.0-1 | — |
| Debian 11 | firefox-esr | 91.9.0esr-1~deb11u1 | DSA-5129-1 |
| Debian 11 | thunderbird | 1:91.9.0-1~deb11u1 | DSA-5141-1 |
| Debian 10 | firefox-esr | 91.9.0esr-1~deb10u1 | DSA-5129-1 |
| Debian 10 | thunderbird | 1:91.9.0-1~deb10u1 | DSA-5141-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 9 | firefox-esr | 91.9.0esr-1~deb9u1 | DLA-2994-1 |
| Debian 9 | thunderbird | 1:91.9.0-1~deb9u1 | DLA-3020-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 22.04 LTS | mozjs78 +1 | No fix yet | — |
| Ubuntu 22.04 LTS | thunderbird | 1:91.9.1+build1-0ubuntu0.22.04.1 | USN-5435-1 |
| Ubuntu 20.04 LTS | firefox | 100.0+build2-0ubuntu0.20.04.1 | USN-5411-1 |
| Ubuntu 20.04 LTS | mozjs52 +1 | No fix yet | — |
| Ubuntu 20.04 LTS | thunderbird | 1:91.9.1+build1-0ubuntu0.20.04.1 | USN-5435-1 |
| Ubuntu 18.04 LTS | firefox | 100.0+build2-0ubuntu0.18.04.1 | USN-5411-1 |
| Ubuntu 18.04 LTS | mozjs38 +1 | No fix yet | — |
| Ubuntu 18.04 LTS | thunderbird | 1:91.9.1+build1-0ubuntu0.18.04.1 | USN-5435-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 9 | firefox | 91.9.0-1.el9_0 | RHSA-2022:4590 |
| RHEL 9 | thunderbird | 91.9.0-3.el9_0 | RHSA-2022:4589 |
| RHEL 8 | firefox | 91.9.0-1.el8_5 | RHSA-2022:1705 |
| RHEL 8 | thunderbird | 91.9.0-3.el8_5 | RHSA-2022:1730 |
| RHEL 7 | firefox | 91.9.0-1.el7_9 | RHSA-2022:1703 |
| RHEL 7 | thunderbird | 91.9.0-3.el7_9 | RHSA-2022:1725 |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8.4 EUS | firefox | 91.9.0-1.el8_4 | RHSA-2022:1702 |
| RHEL 8.4 EUS | thunderbird | 91.9.0-3.el8_4 | RHSA-2022:1726 |
| RHEL 8.2 EUS | firefox | 91.9.0-1.el8_2 | RHSA-2022:1704 |
| RHEL 8.2 EUS | thunderbird | 91.9.0-3.el8_2 | RHSA-2022:1724 |
| RHEL 8.1 E4S | firefox | 91.9.0-1.el8_1 | RHSA-2022:1701 |
| RHEL 8.1 E4S | thunderbird | 91.9.0-3.el8_1 | RHSA-2022:1727 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 8 | firefox | 91.9.0-1.el8_5.alma | ALSA-2022:1705 |
| AlmaLinux 8 | thunderbird | 91.9.0-3.el8_5.alma | ALSA-2022:1730 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 8 | firefox | 91.9.0-1.el8_5 | RLSA-2022:1705 |
| Rocky Linux 8 | thunderbird | 91.9.0-3.el8_5 | RLSA-2022:1730 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP4 | MozillaFirefox | 91.9.0-150200.152.33.1 | SUSE-SU-2022:1748-1, SUSE-RU-2022:1579-1 |
| SLES 15 SP4 | MozillaThunderbird | 91.9.0-150200.8.68.2 | SUSE-SU-2022:1719-1 |
| SLES 15 SP3 | MozillaFirefox | 91.9.0-150200.152.33.1 | SUSE-SU-2022:1748-1, SUSE-RU-2022:1579-1 |
| SLES 15 SP3 | MozillaThunderbird | 91.9.0-150200.8.68.2 | SUSE-SU-2022:1719-1 |
| SLES 15 SP2 | MozillaFirefox | 91.9.0-150200.152.33.1 | SUSE-SU-2022:1748-1, SUSE-RU-2022:1579-1 |
| SLES 15 SP1 | MozillaFirefox | 91.9.0-150000.150.38.3 | SUSE-SU-2022:1731-1 |
| SLES 15 | MozillaFirefox | 91.9.0-150000.150.38.3 | SUSE-SU-2022:1731-1 |
Show 23 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP5 | MozillaFirefox | 91.9.0-112.108.4 | SUSE-SU-2022:1757-1 |
| SLES 12 SP4 | MozillaFirefox | 91.9.0-112.108.4 | SUSE-SU-2022:1757-1 |
| SLES 12 SP3 | MozillaFirefox | 91.9.0-112.108.4 | SUSE-SU-2022:1757-1 |
| SLES 12 SP2 | MozillaFirefox | 91.9.0-112.108.4 | SUSE-SU-2022:1757-1 |
| SLES for SAP 15 SP2 | MozillaFirefox | 91.9.0-150200.152.33.1 | SUSE-SU-2022:1748-1, SUSE-RU-2022:1579-1 |
| SLES for SAP 15 SP1 | MozillaFirefox | 91.9.0-150000.150.38.3 | SUSE-SU-2022:1731-1 |
| SLES for SAP 15 | MozillaFirefox | 91.9.0-150000.150.38.3 | SUSE-SU-2022:1731-1 |
| SLES for SAP 12 SP5 | MozillaFirefox | 91.9.0-112.108.4 | SUSE-SU-2022:1757-1 |
| SLES for SAP 12 SP4 | MozillaFirefox | 91.9.0-112.108.4 | SUSE-SU-2022:1757-1 |
| SLES for SAP 12 SP3 | MozillaFirefox | 91.9.0-112.108.4 | SUSE-SU-2022:1757-1 |
| SLE HPC 15 SP2 | MozillaFirefox | 91.9.0-150200.152.33.1 | SUSE-SU-2022:1748-1, SUSE-RU-2022:1579-1 |
| SLE HPC 15 SP1 | MozillaFirefox | 91.9.0-150000.150.38.3 | SUSE-SU-2022:1731-1 |
| SLE HPC 15 | MozillaFirefox | 91.9.0-150000.150.38.3 | SUSE-SU-2022:1731-1 |
| SUSE OpenStack Cloud Crowbar 9 | MozillaFirefox | 91.9.0-112.108.4 | SUSE-SU-2022:1757-1 |
| SUSE OpenStack Cloud Crowbar 8 | MozillaFirefox | 91.9.0-112.108.4 | SUSE-SU-2022:1757-1 |
| SUSE OpenStack Cloud 9 | MozillaFirefox | 91.9.0-112.108.4 | SUSE-SU-2022:1757-1 |
| SUSE OpenStack Cloud 8 | MozillaFirefox | 91.9.0-112.108.4 | SUSE-SU-2022:1757-1 |
| SUSE Manager Server 4.1 | MozillaFirefox | 91.9.0-150200.152.33.1 | SUSE-SU-2022:1748-1, SUSE-RU-2022:1579-1 |
| SUSE Manager Retail Branch Server 4.1 | MozillaFirefox | 91.9.0-150200.152.33.1 | SUSE-SU-2022:1748-1, SUSE-RU-2022:1579-1 |
| SUSE Manager Proxy 4.1 | MozillaFirefox | 91.9.0-150200.152.33.1 | SUSE-SU-2022:1748-1, SUSE-RU-2022:1579-1 |
| SUSE HPE Helion OpenStack 8 | MozillaFirefox | 91.9.0-112.108.4 | SUSE-SU-2022:1757-1 |
| SUSE Enterprise Storage 7 | MozillaFirefox | 91.9.0-150200.152.33.1 | SUSE-SU-2022:1748-1, SUSE-RU-2022:1579-1 |
| SUSE Enterprise Storage 6 | MozillaFirefox | 91.9.0-150000.150.38.3 | SUSE-SU-2022:1731-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaFirefox | 100.0-1.1 | openSUSE-SU-2024:12044-1 |
| openSUSE Tumbleweed | MozillaThunderbird | 91.9.0-1.1 | openSUSE-SU-2024:12045-1 |
| openSUSE Tumbleweed | firefox-esr | 128.5.1-1.1 | openSUSE-SU-2024:14572-1 |
| openSUSE Leap 15.4 | MozillaFirefox | 91.9.0-150200.152.33.1 | SUSE-SU-2022:1748-1, SUSE-RU-2022:1579-1 |
| openSUSE Leap 15.4 | MozillaThunderbird | 91.9.0-150200.8.68.2 | SUSE-SU-2022:1719-1 |
| openSUSE Leap 15.3 | MozillaFirefox | 91.9.0-150200.152.33.1 | SUSE-SU-2022:1748-1, SUSE-RU-2022:1579-1 |
| openSUSE Leap 15.3 | MozillaThunderbird | 91.9.0-150200.8.68.2 | SUSE-SU-2022:1719-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | librewolf | 100.0-r0 | — |
| Alpine v3.23 | firefox +1 | 100.0-r0 | — |
| Alpine v3.23 | firefox-esr +1 | 91.9.0-r0 | — |
| Alpine v3.22 | firefox +1 | 100.0-r0 | — |
| Alpine v3.22 | firefox-esr +1 | 91.9.0-r0 | — |
| Alpine v3.21 | firefox +1 | 100.0-r0 | — |
| Alpine v3.21 | firefox-esr +1 | 91.9.0-r0 | — |
| Alpine v3.20 | firefox | 100.0-r0 | — |
| Alpine v3.20 | firefox-esr +1 | 91.9.0-r0 | — |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | firefox | 100.0-r0 | — |
| Alpine v3.19 | firefox-esr +1 | 91.9.0-r0 | — |
| Alpine v3.18 | firefox | 100.0-r0 | — |
| Alpine v3.18 | firefox-esr +1 | 91.9.0-r0 | — |
| Alpine v3.17 | firefox | 100.0-r0 | — |
| Alpine v3.17 | firefox-esr +1 | 91.9.0-r0 | — |
| Alpine v3.16 | firefox | 100.0-r0 | — |
| Alpine v3.16 | firefox-esr +1 | 91.9.0-r0 | — |
| Alpine v3.15 | firefox-esr | 91.9.0-r0 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | thunderbird | 91.11.0-2.amzn2.0.1 | ALAS2-2022-1828 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | firefox | 91.9.0-1.0.1.el9_0 | ELSA-2022-4590 |
| Oracle Linux 9 | thunderbird | 91.9.0-3.0.1.el9_0 | ELSA-2022-4589 |
| Oracle Linux 8 | firefox | 91.9.0-1.0.1.el8_5 | ELSA-2022-1705 |
| Oracle Linux 8 | thunderbird | 91.9.0-3.0.1.el8_5 | ELSA-2022-1730 |
| Oracle Linux 7 | firefox | 91.9.0-1.0.1.el7_9 | ELSA-2022-1703 |
| Oracle Linux 7 | thunderbird | 91.9.0-3.0.1.el7_9 | ELSA-2022-1725 |
Advisories 40
- ALSA-2022:1705 Important: firefox security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2022:1730 Important: thunderbird security update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2022:1725 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2022:1703 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- USN-5435-1 thunderbird vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- USN-5411-1 firefox vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DSA-5141-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-5129-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-3020-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2994-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- RLSA-2022:1730 Important: thunderbird security update Rocky Linux Security Advisories · Feb 5, 2026
- RLSA-2022:1705 Important: firefox security update Rocky Linux Security Advisories · Feb 5, 2026
- SUSE-RU-2022:1579-1 Recommended update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:12045-1 MozillaThunderbird-91.9.0-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2022:1731-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2022:1757-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2022:1748-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2022:1719-1 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
- RHSA-2022:4590 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2022:4589 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2022:1730 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2022:1727 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2022:1726 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2022:1724 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2022:1705 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2022:1704 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2022:1701 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2022:1702 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- WID-SEC-2022-1335 Xerox FreeFlow Print Server: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 6, 2025
- openSUSE-SU-2024:12044-1 MozillaFirefox-100.0-1.1 on GA media SUSE / openSUSE Security Updates · May 7, 2025
- WID-SEC-2022-0537 Mozilla Firefox und Mozilla Firefox ESR: Mehrere Schwachstellen BSI CERT-Bund (WID) · Apr 1, 2025
- WID-SEC-2022-0538 Mozilla Thunderbird: Mehrere Schwachstellen BSI CERT-Bund (WID) · Apr 1, 2025
- ALAS2-2022-1828 Important: thunderbird security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Jul 3, 2024
- ELSA-2022-4590 Important: firefox security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jun 30, 2022
- ELSA-2022-4589 Important: thunderbird security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jun 30, 2022
- ELSA-2022-1730 Important: thunderbird security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · May 5, 2022
- ELSA-2022-1725 Important: thunderbird security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · May 5, 2022
- ELSA-2022-1703 Important: firefox security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · May 4, 2022
- ELSA-2022-1705 Important: firefox security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · May 4, 2022