Description
URLs using "javascript:" have the protocol removed when pasted into the addressbar to protect users from cross-site scripting (XSS) attacks, but if a tab character is embedded in the "javascript:" URL the protocol is not removed and the script will execute. This could allow users to be socially engineered to run an XSS attack against themselves. This vulnerability affects Firefox < 59.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Firefox | unspecified – < 59 | 59 |
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 18.04 LTS | firefox | 59.0.1+build1-0ubuntu1 | — |
| Ubuntu 16.04 LTS | firefox | 59.0+build5-0ubuntu0.16.04.1 | USN-3596-1 |
| Ubuntu 14.04 LTS | firefox | 59.0+build5-0ubuntu0.14.04.1 | USN-3596-1 |
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 |
Advisories 3
- USN-3596-1 firefox vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 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
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1422643
- 103386 vdb-entry
- 1040514 vdb-entry
- USN-3596-1 vendor-advisory
- https://www.mozilla.org/security/advisories/mfsa2018-06/