Description
Due to incorrect JIT optimization, we incorrectly interpreted data from the wrong type of object, resulting in the potential leak of a single bit of memory. This vulnerability affects Firefox < 91 and Thunderbird < 91.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Firefox | unspecified – < 91 | 91 |
| Mozilla | Thunderbird | 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.
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 | 1:91.5.0+build1-0ubuntu0.20.04.1 | USN-5248-1 |
| 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 | 1:91.5.0+build1-0ubuntu0.18.04.1 | USN-5248-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP3 | MozillaFirefox | 91.2.0-8.54.1 | SUSE-SU-2021:3451-1 |
| SLES 15 SP3 | MozillaFirefox-branding-SLE | 91-9.5.1 | SUSE-SU-2021:3451-1 |
| SLES 15 SP3 | MozillaThunderbird | 91.4.0-8.45.2 | SUSE-SU-2021:4150-1 |
| SLES 15 SP2 | MozillaFirefox | 91.2.0-8.54.1 | SUSE-SU-2021:3451-1 |
| SLES 15 SP2 | MozillaFirefox-branding-SLE | 91-9.5.1 | SUSE-SU-2021:3451-1 |
| SLES 15 SP2 | MozillaThunderbird | 91.4.0-8.45.2 | SUSE-SU-2021:4150-1 |
| SLES 15 SP1 | MozillaFirefox | 91.2.0-3.155.2 | SUSE-SU-2022:1577-1, SUSE-SU-2021:3331-1 |
| SLES 15 SP1 | MozillaFirefox-branding-SLE | 91-4.19.1 | SUSE-SU-2021:3331-1 |
| SLES 15 | MozillaFirefox | 91.2.0-3.155.2 | SUSE-SU-2022:1577-1, SUSE-SU-2021:3331-1 |
| SLES 15 | MozillaFirefox-branding-SLE | 91-4.19.1 | SUSE-SU-2021:3331-1 |
| SLES 12 SP5 | MozillaFirefox | 91.1.0-112.71.1 | SUSE-SU-2022:1582-1, SUSE-SU-2021:3191-1 |
| SLES 12 SP5 | MozillaFirefox-branding-SLE | 91-35.6.6 | SUSE-SU-2021:3191-1 |
Show 17 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP4 | MozillaFirefox | 91.1.0-112.71.1 | SUSE-SU-2022:1582-1, SUSE-SU-2021:3191-1 |
| SLES 12 SP4 | MozillaFirefox-branding-SLE | 91-35.6.6 | SUSE-SU-2021:3191-1 |
| SLES 12 SP3 | MozillaFirefox | 91.1.0-112.71.1 | SUSE-SU-2022:1582-1, SUSE-SU-2021:3191-1 |
| SLES 12 SP3 | MozillaFirefox-branding-SLE | 91-35.6.6 | SUSE-SU-2021:3191-1 |
| SLES 12 SP2 | MozillaFirefox | 91.1.0-112.71.1 | SUSE-SU-2022:1582-1, SUSE-SU-2021:3191-1 |
| SLES 12 SP2 | MozillaFirefox-branding-SLE | 91-35.6.6 | SUSE-SU-2021:3191-1 |
| SLES 11 SP4 | MozillaFirefox | 78.14.0-78.140.4 | SUSE-SU-2021:14826-1, SUSE-SU-2021:14821-1 |
| SLES 11 SP4 | MozillaFirefox-branding-SLED | 91-21.18.1 | SUSE-SU-2021:14826-1 |
| SLES for SAP 15 SP1 | MozillaFirefox | 91.2.0-3.155.2 | SUSE-SU-2022:1577-1, SUSE-SU-2021:3331-1 |
| SLES for SAP 15 SP1 | MozillaFirefox-branding-SLE | 91-4.19.1 | SUSE-SU-2021:3331-1 |
| SLES for SAP 15 | MozillaFirefox | 91.2.0-3.155.2 | SUSE-SU-2022:1577-1, SUSE-SU-2021:3331-1 |
| SLES for SAP 15 | MozillaFirefox-branding-SLE | 91-4.19.1 | SUSE-SU-2021:3331-1 |
| SLES for SAP 12 SP5 | MozillaFirefox | 91.1.0-112.71.1 | SUSE-SU-2022:1582-1, SUSE-SU-2021:3191-1 |
| SLES for SAP 12 SP5 | MozillaFirefox-branding-SLE | 91-35.6.6 | SUSE-SU-2021:3191-1 |
| SLES for SAP 12 SP4 | MozillaFirefox | 91.1.0-112.71.1 | SUSE-SU-2022:1582-1, SUSE-SU-2021:3191-1 |
| SLES for SAP 12 SP4 | MozillaFirefox-branding-SLE | 91-35.6.6 | SUSE-SU-2021:3191-1 |
| SLES for SAP 12 SP3 | MozillaFirefox | 91.1.0-112.71.1 | SUSE-SU-2022:1582-1, SUSE-SU-2021:3191-1 |
| SLES for SAP 12 SP3 | MozillaFirefox-branding-SLE | 91-35.6.6 | SUSE-SU-2021:3191-1 |
| SLE HPC 15 SP1 | MozillaFirefox | 91.2.0-3.155.2 | SUSE-SU-2022:1577-1, SUSE-SU-2021:3331-1 |
| SLE HPC 15 SP1 | MozillaFirefox-branding-SLE | 91-4.19.1 | SUSE-SU-2021:3331-1 |
| SLE HPC 15 | MozillaFirefox | 91.2.0-3.155.2 | SUSE-SU-2022:1577-1, SUSE-SU-2021:3331-1 |
| SLE HPC 15 | MozillaFirefox-branding-SLE | 91-4.19.1 | SUSE-SU-2021:3331-1 |
| SUSE OpenStack Cloud Crowbar 9 | MozillaFirefox | 91.1.0-112.71.1 | SUSE-SU-2022:1582-1, SUSE-SU-2021:3191-1 |
| SUSE OpenStack Cloud Crowbar 9 | MozillaFirefox-branding-SLE | 91-35.6.6 | SUSE-SU-2021:3191-1 |
| SUSE OpenStack Cloud Crowbar 8 | MozillaFirefox | 91.1.0-112.71.1 | SUSE-SU-2022:1582-1, SUSE-SU-2021:3191-1 |
| SUSE OpenStack Cloud Crowbar 8 | MozillaFirefox-branding-SLE | 91-35.6.6 | SUSE-SU-2021:3191-1 |
| SUSE OpenStack Cloud 9 | MozillaFirefox | 91.1.0-112.71.1 | SUSE-SU-2022:1582-1, SUSE-SU-2021:3191-1 |
| SUSE OpenStack Cloud 9 | MozillaFirefox-branding-SLE | 91-35.6.6 | SUSE-SU-2021:3191-1 |
| SUSE OpenStack Cloud 8 | MozillaFirefox | 91.1.0-112.71.1 | SUSE-SU-2022:1582-1, SUSE-SU-2021:3191-1 |
| SUSE OpenStack Cloud 8 | MozillaFirefox-branding-SLE | 91-35.6.6 | SUSE-SU-2021:3191-1 |
| SUSE HPE Helion OpenStack 8 | MozillaFirefox | 91.1.0-112.71.1 | SUSE-SU-2022:1582-1, SUSE-SU-2021:3191-1 |
| SUSE HPE Helion OpenStack 8 | MozillaFirefox-branding-SLE | 91-35.6.6 | SUSE-SU-2021:3191-1 |
| SUSE Enterprise Storage 6 | MozillaFirefox | 91.2.0-3.155.2 | SUSE-SU-2022:1577-1, SUSE-SU-2021:3331-1 |
| 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 | firefox-esr | 128.5.1-1.1 | openSUSE-SU-2024:14572-1 |
| openSUSE Leap 15.3 | MozillaFirefox | 91.2.0-8.54.1 | openSUSE-SU-2021:3451-1 |
| openSUSE Leap 15.3 | MozillaFirefox-branding-SLE | 91-9.5.1 | openSUSE-SU-2021:3451-1 |
| openSUSE Leap 15.3 | MozillaThunderbird | 91.4.0-8.45.2 | openSUSE-SU-2021:4150-1 |
| openSUSE Leap 15.3 | rust-cbindgen | 0.19.0-1.9.1 | openSUSE-SU-2021:3331-1 |
| openSUSE Leap 15.2 | MozillaFirefox | 91.2.0-lp152.2.67.1 | openSUSE-SU-2021:1367-1 |
| openSUSE Leap 15.2 | MozillaThunderbird | 91.4.0-lp152.2.52.1 | openSUSE-SU-2021:1635-1 |
| 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 | thunderbird | 91.3.2-r0 | — |
| Alpine v3.22 | firefox +1 | 92.0.1-r0 | — |
| Alpine v3.22 | thunderbird | 91.3.2-r0 | — |
| Alpine v3.21 | firefox +1 | 92.0.1-r0 | — |
| Alpine v3.21 | thunderbird | 91.3.2-r0 | — |
| Alpine v3.20 | firefox | 92.0.1-r0 | — |
| Alpine v3.20 | thunderbird | 91.3.2-r0 | — |
Show 5 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 | thunderbird | 91.3.2-r0 | — |
| Alpine v3.18 | firefox | 92.0.1-r0 | — |
| Alpine v3.18 | thunderbird | 91.3.2-r0 | — |
| Alpine v3.17 | firefox | 92.0.1-r0 | — |
| Alpine v3.17 | thunderbird | 91.3.2-r0 | — |
| Alpine v3.16 | firefox | 92.0.1-r0 | — |
| Alpine v3.16 | thunderbird | 91.3.2-r0 | — |
| Alpine v3.15 | firefox | 92.0.1-r0 | — |
Advisories 17
- USN-5248-1 thunderbird vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- USN-5037-1 firefox vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- openSUSE-SU-2021:3331-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:4150-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2022:1582-1 Security update for MozillaFirefox 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
- openSUSE-SU-2021:4150-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:1635-1 Security update for MozillaThunderbird 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-2021:3331-1 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