Description
A flaw in handling fullscreen transitions may have inadvertently caused the application to become stuck in fullscreen mode when a modal dialog was opened during the transition. This issue left users unable to exit fullscreen mode using standard actions like pressing "Esc" or accessing right-click menus, resulting in a disrupted browsing experience until the browser is restarted.
*This bug only affects the application when running on macOS. Other operating systems are unaffected.* This vulnerability affects Firefox < 133, Firefox ESR < 128.5, Thunderbird < 133, and Thunderbird < 128.5.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Firefox | unspecified – < 133 | 133 |
| Mozilla | Firefox ESR | unspecified – < 128.5 | 128.5 |
| Mozilla | Thunderbird | unspecified – < 133, unspecified – < 128.5 | 133 |
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.
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP6 | MozillaFirefox | 128.5.0-150200.152.161.1 | SUSE-SU-2024:4086-1 |
| SLES 15 SP6 | MozillaThunderbird | 128.5.0-150200.8.191.1 | SUSE-SU-2024:4148-1 |
| SLES 15 SP5 | MozillaFirefox | 128.5.0-150200.152.161.1 | SUSE-SU-2024:4086-1 |
| SLES 15 SP5 | MozillaThunderbird | 128.5.0-150200.8.191.1 | SUSE-SU-2024:4148-1 |
| SLES 15 SP4 | MozillaFirefox | 128.5.0-150200.152.161.1 | SUSE-SU-2024:4086-1 |
| SLES 15 SP3 | MozillaFirefox | 128.5.0-150200.152.161.1 | SUSE-SU-2024:4086-1 |
| SLES 15 SP2 | MozillaFirefox | 128.5.0-150200.152.161.1 | SUSE-SU-2024:4086-1 |
Show 8 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP5 | MozillaFirefox | 128.5.0-112.237.2 | SUSE-SU-2024:4074-1 |
| SLES for SAP 15 SP4 | MozillaFirefox | 128.5.0-150200.152.161.1 | SUSE-SU-2024:4086-1 |
| SLES for SAP 15 SP3 | MozillaFirefox | 128.5.0-150200.152.161.1 | SUSE-SU-2024:4086-1 |
| SLES for SAP 15 SP2 | MozillaFirefox | 128.5.0-150200.152.161.1 | SUSE-SU-2024:4086-1 |
| SLE HPC 15 SP4 | MozillaFirefox | 128.5.0-150200.152.161.1 | SUSE-SU-2024:4086-1 |
| SLE HPC 15 SP3 | MozillaFirefox | 128.5.0-150200.152.161.1 | SUSE-SU-2024:4086-1 |
| SLE HPC 15 SP2 | MozillaFirefox | 128.5.0-150200.152.161.1 | SUSE-SU-2024:4086-1 |
| SUSE Enterprise Storage 7.1 | MozillaFirefox | 128.5.0-150200.152.161.1 | SUSE-SU-2024:4086-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaFirefox | 133.0.3-1.1 | openSUSE-SU-2024:14583-1 |
| openSUSE Tumbleweed | MozillaThunderbird | 128.5.0-1.1 | openSUSE-SU-2024:14533-1 |
| openSUSE Tumbleweed | firefox-esr | 128.5.1-1.1 | openSUSE-SU-2024:14572-1 |
| openSUSE Leap 15.6 | MozillaFirefox | 128.5.0-150200.152.161.1 | SUSE-SU-2024:4086-1 |
| openSUSE Leap 15.6 | MozillaThunderbird | 128.5.0-150200.8.191.1 | SUSE-SU-2024:4148-1 |
| openSUSE Leap 15.5 | MozillaFirefox | 128.5.0-150200.152.161.1 | SUSE-SU-2024:4086-1 |
| openSUSE Leap 15.5 | MozillaThunderbird | 128.5.0-150200.8.191.1 | SUSE-SU-2024:4148-1 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | firefox | 133.0-r0 | — |
Advisories 7
- WID-SEC-2024-3549 Mozilla Firefox und Thunderbird: Mehrere Schwachstellen BSI CERT-Bund (WID) · May 31, 2026
- SUSE-SU-2024:4074-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2024:4148-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:14583-1 MozillaFirefox-133.0.3-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2024:4086-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:14533-1 MozillaThunderbird-128.5.0-1.1 on GA media 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