Description
Firefox's HTML parser did not correctly interpret HTML comment tags, resulting in an incongruity with other browsers. This could have been used to escape HTML comments on pages that put user-controlled data in them. This vulnerability affects Firefox < 101.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Firefox | unspecified – < 101 | 101 |
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 +1 | No fix yet | — |
| Ubuntu 20.04 LTS | firefox | 101.0.1+build1-0ubuntu0.20.04.1 | USN-5475-1 |
| Ubuntu 20.04 LTS | mozjs52 +1 | No fix yet | — |
| Ubuntu 18.04 LTS | firefox | 101.0.1+build1-0ubuntu0.18.04.1 | USN-5475-1 |
| Ubuntu 18.04 LTS | mozjs38 +1 | No fix yet | — |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaFirefox | 101.0-1.1 | openSUSE-SU-2024:12121-1 |
| 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 | 101.0-r0 | — |
| Alpine v3.23 | firefox +1 | 101.0-r0 | — |
| Alpine v3.22 | firefox +1 | 101.0-r0 | — |
| Alpine v3.21 | firefox +1 | 101.0-r0 | — |
| Alpine v3.20 | firefox | 101.0-r0 | — |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | firefox | 101.0-r0 | — |
| Alpine v3.18 | firefox | 101.0-r0 | — |
| Alpine v3.17 | firefox | 101.0-r0 | — |
| Alpine v3.16 | firefox | 101.0-r0 | — |
Advisories 4
- USN-5475-1 firefox vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- openSUSE-SU-2024:12121-1 MozillaFirefox-101.0-1.1 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
- WID-SEC-2022-0019 Mozilla Firefox und Thunderbird: Mehrere Schwachstellen ermöglichen Codeausführung BSI CERT-Bund (WID) · Jul 10, 2024