Description
Uninitialized memory in a canvas object could have caused an incorrect free() leading to memory corruption and a potentially exploitable crash. This vulnerability affects Thunderbird < 78.13, Thunderbird < 91, Firefox ESR < 78.13, and Firefox < 91.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Thunderbird | unspecified – < 78.13, unspecified – < 91 | 78.13 |
| Mozilla | Firefox ESR | unspecified – < 78.13 | 78.13 |
| Mozilla | Firefox | unspecified – < 91 | 91 |
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 | 78.13.0esr-1 | — |
| Debian 14 | thunderbird | 1:78.13.0-1 | — |
| Debian 13 | firefox-esr | 78.13.0esr-1 | — |
| Debian 13 | thunderbird | 1:78.13.0-1 | — |
| Debian 12 | firefox-esr | 78.13.0esr-1 | — |
| Debian 12 | thunderbird | 1:78.13.0-1 | — |
| Debian 11 | firefox-esr | 78.13.0esr-1~deb11u1 | DSA-4956-1 |
| Debian 11 | thunderbird | 1:78.13.0-1~deb11u1 | DSA-4959-1 |
| Debian 10 | firefox-esr | 78.13.0esr-1~deb10u1 | DSA-4956-1 |
| Debian 10 | thunderbird | 1:78.13.0-1~deb10u1 | DSA-4959-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 9 | firefox-esr | 78.13.0esr-1~deb9u1 | DLA-2740-1 |
| Debian 9 | thunderbird | 1:78.13.0-1~deb9u1 | DLA-2745-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 22.04 LTS | mozjs78 | No fix yet | — |
| Ubuntu 20.04 LTS | firefox | 91.0+build2-0ubuntu0.20.04.1 | USN-5037-1 |
| 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 | 91.0+build2-0ubuntu0.18.04.1 | USN-5037-1 |
| 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 | 78.13.0-2.el8_4 | RHSA-2021:3157 |
| RHEL 8 | thunderbird | 78.13.0-1.el8_4 | RHSA-2021:3155 |
| RHEL 7 | firefox | 78.13.0-2.el7_9 | RHSA-2021:3154 |
| RHEL 7 | thunderbird | 78.13.0-1.el7_9 | RHSA-2021:3160 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8.2 EUS | firefox | 78.13.0-2.el8_2 | RHSA-2021:3156 |
| RHEL 8.2 EUS | thunderbird | 78.13.0-1.el8_2 | RHSA-2021:3162 |
| RHEL 8.1 EUS | firefox | 78.13.0-2.el8_1 | RHSA-2021:3159 |
| RHEL 8.1 EUS | thunderbird | 78.13.0-1.el8_1 | RHSA-2021:3161 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 8 | firefox | 78.13.0-2.el8 | RLSA-2021:3157 |
| Rocky Linux 8 | thunderbird | 78.13.0-1.el8 | RLSA-2021:3155 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP3 | MozillaFirefox | 78.13.0-8.49.1 | SUSE-SU-2021:3451-1, SUSE-SU-2021:2774-1 |
| SLES 15 SP3 | MozillaFirefox-branding-SLE | 91-9.5.1 | SUSE-SU-2021:3451-1 |
| SLES 15 SP3 | MozillaThunderbird | 78.13.0-8.36.1 | SUSE-SU-2021:2874-1 |
| SLES 15 SP2 | MozillaFirefox | 78.13.0-8.49.1 | SUSE-SU-2021:3451-1, SUSE-SU-2021:2774-1 |
| SLES 15 SP2 | MozillaFirefox-branding-SLE | 91-9.5.1 | SUSE-SU-2021:3451-1 |
| SLES 15 SP2 | MozillaThunderbird | 78.13.0-8.36.1 | SUSE-SU-2021:2874-1 |
| SLES 15 SP1 | MozillaFirefox | 78.13.0-3.150.1 | SUSE-SU-2022:1577-1, SUSE-SU-2021:3331-1, SUSE-SU-2021:2694-1 |
| SLES 15 SP1 | MozillaFirefox-branding-SLE | 91-4.19.1 | SUSE-SU-2021:3331-1 |
| SLES 15 | MozillaFirefox | 78.13.0-3.150.1 | SUSE-SU-2022:1577-1, SUSE-SU-2021:3331-1, SUSE-SU-2021:2694-1 |
| SLES 15 | MozillaFirefox-branding-SLE | 91-4.19.1 | SUSE-SU-2021:3331-1 |
| SLES 12 SP5 | MozillaFirefox | 78.13.0-112.68.1 | SUSE-SU-2022:1582-1, SUSE-SU-2021:3191-1, SUSE-SU-2021:2691-1 |
| SLES 12 SP5 | MozillaFirefox-branding-SLE | 91-35.6.6 | SUSE-SU-2021:3191-1 |
Show 20 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP4 | MozillaFirefox | 78.13.0-112.68.1 | SUSE-SU-2022:1582-1, SUSE-SU-2021:3191-1, SUSE-SU-2021:2691-1 |
| SLES 12 SP4 | MozillaFirefox-branding-SLE | 91-35.6.6 | SUSE-SU-2021:3191-1 |
| SLES 12 SP3 | MozillaFirefox | 78.13.0-112.68.1 | SUSE-SU-2022:1582-1, SUSE-SU-2021:3191-1, SUSE-SU-2021:2691-1 |
| SLES 12 SP3 | MozillaFirefox-branding-SLE | 91-35.6.6 | SUSE-SU-2021:3191-1 |
| SLES 12 SP2 | MozillaFirefox | 78.13.0-112.68.1 | SUSE-SU-2022:1582-1, SUSE-SU-2021:3191-1, SUSE-SU-2021:2691-1 |
| SLES 12 SP2 | MozillaFirefox-branding-SLE | 91-35.6.6 | SUSE-SU-2021:3191-1 |
| SLES 11 SP4 | MozillaFirefox | 78.13.0-78.137.1 | SUSE-SU-2021:14826-1, SUSE-SU-2021:14821-1, SUSE-SU-2021:14782-1 |
| SLES 11 SP4 | MozillaFirefox-branding-SLED | 91-21.18.1 | SUSE-SU-2021:14826-1 |
| SLES for SAP 15 SP1 | MozillaFirefox | 78.13.0-3.150.1 | SUSE-SU-2022:1577-1, SUSE-SU-2021:3331-1, SUSE-SU-2021:2694-1 |
| SLES for SAP 15 SP1 | MozillaFirefox-branding-SLE | 91-4.19.1 | SUSE-SU-2021:3331-1 |
| SLES for SAP 15 | MozillaFirefox | 78.13.0-3.150.1 | SUSE-SU-2022:1577-1, SUSE-SU-2021:3331-1, SUSE-SU-2021:2694-1 |
| SLES for SAP 15 | MozillaFirefox-branding-SLE | 91-4.19.1 | SUSE-SU-2021:3331-1 |
| SLES for SAP 12 SP5 | MozillaFirefox | 78.13.0-112.68.1 | SUSE-SU-2022:1582-1, SUSE-SU-2021:3191-1, SUSE-SU-2021:2691-1 |
| SLES for SAP 12 SP5 | MozillaFirefox-branding-SLE | 91-35.6.6 | SUSE-SU-2021:3191-1 |
| SLES for SAP 12 SP4 | MozillaFirefox | 78.13.0-112.68.1 | SUSE-SU-2022:1582-1, SUSE-SU-2021:3191-1, SUSE-SU-2021:2691-1 |
| SLES for SAP 12 SP4 | MozillaFirefox-branding-SLE | 91-35.6.6 | SUSE-SU-2021:3191-1 |
| SLES for SAP 12 SP3 | MozillaFirefox | 78.13.0-112.68.1 | SUSE-SU-2022:1582-1, SUSE-SU-2021:3191-1, SUSE-SU-2021:2691-1 |
| SLES for SAP 12 SP3 | MozillaFirefox-branding-SLE | 91-35.6.6 | SUSE-SU-2021:3191-1 |
| SLE HPC 15 SP1 | MozillaFirefox | 78.13.0-3.150.1 | SUSE-SU-2022:1577-1, SUSE-SU-2021:3331-1, SUSE-SU-2021:2694-1 |
| SLE HPC 15 SP1 | MozillaFirefox-branding-SLE | 91-4.19.1 | SUSE-SU-2021:3331-1 |
| SLE HPC 15 | MozillaFirefox | 78.13.0-3.150.1 | SUSE-SU-2022:1577-1, SUSE-SU-2021:3331-1, SUSE-SU-2021:2694-1 |
| SLE HPC 15 | MozillaFirefox-branding-SLE | 91-4.19.1 | SUSE-SU-2021:3331-1 |
| SUSE OpenStack Cloud Crowbar 9 | MozillaFirefox | 78.13.0-112.68.1 | SUSE-SU-2022:1582-1, SUSE-SU-2021:3191-1, SUSE-SU-2021:2691-1 |
| SUSE OpenStack Cloud Crowbar 9 | MozillaFirefox-branding-SLE | 91-35.6.6 | SUSE-SU-2021:3191-1 |
| SUSE OpenStack Cloud Crowbar 8 | MozillaFirefox | 78.13.0-112.68.1 | SUSE-SU-2022:1582-1, SUSE-SU-2021:3191-1, SUSE-SU-2021:2691-1 |
| SUSE OpenStack Cloud Crowbar 8 | MozillaFirefox-branding-SLE | 91-35.6.6 | SUSE-SU-2021:3191-1 |
| SUSE OpenStack Cloud 9 | MozillaFirefox | 78.13.0-112.68.1 | SUSE-SU-2022:1582-1, SUSE-SU-2021:3191-1, SUSE-SU-2021:2691-1 |
| SUSE OpenStack Cloud 9 | MozillaFirefox-branding-SLE | 91-35.6.6 | SUSE-SU-2021:3191-1 |
| SUSE OpenStack Cloud 8 | MozillaFirefox | 78.13.0-112.68.1 | SUSE-SU-2022:1582-1, SUSE-SU-2021:3191-1, SUSE-SU-2021:2691-1 |
| SUSE OpenStack Cloud 8 | MozillaFirefox-branding-SLE | 91-35.6.6 | SUSE-SU-2021:3191-1 |
| SUSE Manager Server 4.0 | MozillaFirefox | 78.13.0-3.150.1 | SUSE-SU-2021:2694-1 |
| SUSE Manager Retail Branch Server 4.0 | MozillaFirefox | 78.13.0-3.150.1 | SUSE-SU-2021:2694-1 |
| SUSE Manager Proxy 4.0 | MozillaFirefox | 78.13.0-3.150.1 | SUSE-SU-2021:2694-1 |
| SUSE HPE Helion OpenStack 8 | MozillaFirefox | 78.13.0-112.68.1 | SUSE-SU-2022:1582-1, SUSE-SU-2021:3191-1, SUSE-SU-2021:2691-1 |
| SUSE HPE Helion OpenStack 8 | MozillaFirefox-branding-SLE | 91-35.6.6 | SUSE-SU-2021:3191-1 |
| SUSE Enterprise Storage 6 | MozillaFirefox | 78.13.0-3.150.1 | SUSE-SU-2022:1577-1, SUSE-SU-2021:3331-1, SUSE-SU-2021:2694-1 |
| SUSE Enterprise Storage 6 | MozillaFirefox-branding-SLE | 91-4.19.1 | SUSE-SU-2021:3331-1 |
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 | 78.13.0-8.49.1 | openSUSE-SU-2021:3451-1, openSUSE-SU-2021:2774-1 |
| openSUSE Leap 15.3 | MozillaFirefox-branding-SLE | 91-9.5.1 | openSUSE-SU-2021:3451-1 |
| openSUSE Leap 15.3 | MozillaThunderbird | 78.13.0-8.36.1 | openSUSE-SU-2021:2874-1 |
| openSUSE Leap 15.3 | rust-cbindgen | 0.19.0-1.9.1 | openSUSE-SU-2021:3331-1 |
| openSUSE Leap 15.2 | MozillaFirefox | 78.13.0-lp152.2.64.1 | openSUSE-SU-2021:1367-1, openSUSE-SU-2021:1184-1 |
| openSUSE Leap 15.2 | rust-cbindgen | 0.19.0-lp152.2.7.1 | openSUSE-SU-2021:1367-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | librewolf | 92.0.1-r0 | — |
| Alpine v3.23 | firefox +1 | 92.0.1-r0 | — |
| Alpine v3.23 | firefox-esr | 78.13.0-r0 | — |
| Alpine v3.23 | thunderbird | 91.3.2-r0 | — |
| Alpine v3.22 | firefox +1 | 92.0.1-r0 | — |
| Alpine v3.22 | firefox-esr | 78.13.0-r0 | — |
| Alpine v3.22 | thunderbird | 91.3.2-r0 | — |
| Alpine v3.21 | firefox +1 | 92.0.1-r0 | — |
| Alpine v3.21 | firefox-esr | 78.13.0-r0 | — |
| Alpine v3.21 | thunderbird | 91.3.2-r0 | — |
| Alpine v3.20 | firefox | 92.0.1-r0 | — |
| Alpine v3.20 | firefox-esr | 78.13.0-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 | 92.0.1-r0 | — |
| Alpine v3.19 | firefox-esr | 78.13.0-r0 | — |
| Alpine v3.19 | thunderbird | 91.3.2-r0 | — |
| Alpine v3.18 | firefox | 92.0.1-r0 | — |
| Alpine v3.18 | firefox-esr | 78.13.0-r0 | — |
| Alpine v3.18 | thunderbird | 91.3.2-r0 | — |
| Alpine v3.17 | firefox | 92.0.1-r0 | — |
| Alpine v3.17 | firefox-esr | 78.13.0-r0 | — |
| Alpine v3.17 | thunderbird | 91.3.2-r0 | — |
| Alpine v3.16 | firefox | 92.0.1-r0 | — |
| Alpine v3.16 | firefox-esr | 78.13.0-r0 | — |
| Alpine v3.16 | thunderbird | 91.3.2-r0 | — |
| Alpine v3.15 | firefox | 92.0.1-r0 | — |
| Alpine v3.15 | firefox-esr | 78.13.0-r0 | — |
| Alpine v3.14 | firefox-esr | 78.13.0-r0 | — |
| Alpine v3.13 | firefox-esr | 78.13.0-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 | 78.13.0-2.0.1.el8_4 | ELSA-2021-3157 |
| Oracle Linux 8 | thunderbird | 78.13.0-1.0.1.el8_4 | ELSA-2021-3155 |
| Oracle Linux 7 | firefox | 78.13.0-2.0.1.el7_9 | ELSA-2021-3154 |
| Oracle Linux 7 | thunderbird | 78.13.0-1.0.1.el7_9 | ELSA-2021-3160 |
Advisories 42
- RHSA-2021:3160 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2021:3154 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-5037-1 firefox vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DSA-4956-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-4959-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2745-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2740-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- RLSA-2021:3155 Important: thunderbird security update Rocky Linux Security Advisories · Feb 5, 2026
- RLSA-2021:3157 Important: firefox security update Rocky Linux Security Advisories · Feb 4, 2026
- SUSE-SU-2021:14782-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:2691-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:3331-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:2774-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2022:1582-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:2874-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:14826-1 Security update for MozillaFirefox, rust-cbindgen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:2694-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:1184-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:2774-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:14821-1 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-2021:2874-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:3331-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:3451-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:1367-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2022:1577-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:3451-1 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-2021:3191-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- RHSA-2021:3162 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2021:3161 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2021:3159 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2021:3157 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2021:3155 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- RHSA-2021:3156 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-2021-3155 Important: thunderbird security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Aug 17, 2021
- ELSA-2021-3154 Important: firefox security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Aug 17, 2021
- ELSA-2021-3160 Important: thunderbird security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Aug 17, 2021
- ELSA-2021-3157 Important: firefox security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Aug 17, 2021
References
- https://www.mozilla.org/security/advisories/mfsa2021-33/
- https://www.mozilla.org/security/advisories/mfsa2021-35/
- https://www.mozilla.org/security/advisories/mfsa2021-34/
- https://www.mozilla.org/security/advisories/mfsa2021-36/
- https://bugzilla.mozilla.org/show_bug.cgi?id=1722204
- GLSA-202202-03 vendor-advisory
- GLSA-202208-14 vendor-advisory