Description
When a link to an external protocol was clicked, a prompt was presented that allowed the user to choose what application to open it in. An attacker could induce that prompt to be associated with an origin they didn't control, resulting in a spoofing attack. This was fixed by changing external protocol prompts to be tab-modal while also ensuring they could not be incorrectly associated with a different origin. This vulnerability affects Firefox < 82.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Firefox | unspecified – < 82 | 82 |
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 20.04 LTS | firefox | 82.0+build2-0ubuntu0.20.04.1 | USN-4599-1 |
| Ubuntu 20.04 LTS | mozjs52 +1 | No fix yet | — |
| Ubuntu 18.04 LTS | firefox | 82.0+build2-0ubuntu0.18.04.1 | USN-4599-1 |
| Ubuntu 18.04 LTS | mozjs38 +1 | No fix yet | — |
| Ubuntu 16.04 LTS | firefox | 82.0+build2-0ubuntu0.16.04.5 | USN-4599-2 |
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 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | librewolf | 82.0-r0 | — |
| Alpine v3.23 | firefox +1 | 82.0-r0 | — |
| Alpine v3.22 | firefox +1 | 82.0-r0 | — |
| Alpine v3.21 | firefox +1 | 82.0-r0 | — |
| Alpine v3.20 | firefox | 82.0-r0 | — |
Show 8 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | firefox | 82.0-r0 | — |
| Alpine v3.18 | firefox | 82.0-r0 | — |
| Alpine v3.17 | firefox | 82.0-r0 | — |
| Alpine v3.16 | firefox | 82.0-r0 | — |
| Alpine v3.15 | firefox | 82.0-r0 | — |
| Alpine v3.14 | firefox | 82.0-r0 | — |
| Alpine v3.13 | firefox | 82.0-r0 | — |
| Alpine v3.12 | firefox | 82.0-r0 | — |
Advisories 4
- USN-4599-2 firefox vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- USN-4599-1 firefox vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- openSUSE-SU-2024:10600-1 MozillaFirefox-92.0-1.2 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