Description
Mozilla Firefox before 43.0 mishandles the # (number sign) character in a data: URI, which allows remote attackers to spoof web sites via unspecified vectors.
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 14.04 LTS | firefox | 43.0+build1-0ubuntu0.14.04.1 | USN-2833-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaFirefox | 50.1.0-1.1 | openSUSE-SU-2024:10071-1 |
| openSUSE Tumbleweed | firefox-esr | 128.5.1-1.1 | openSUSE-SU-2024:14572-1 |
Advisories 3
- USN-2833-1 firefox vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- openSUSE-SU-2024:14572-1 firefox-esr-128.5.1-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:10071-1 MozillaFirefox-50.1.0-1.1 on GA media SUSE / openSUSE Security Updates · May 7, 2025
References
- GLSA-201512-10 vendor-advisory
- openSUSE-SU-2015:2353 vendor-advisory
- https://bugzilla.mozilla.org/show_bug.cgi?id=1221444
- openSUSE-SU-2016:0308 vendor-advisory
- FEDORA-2015-7ab3d3afcf vendor-advisory
- USN-2833-1 vendor-advisory
- http://www.mozilla.org/security/announce/2015/mfsa2015-141.html
- 79280 vdb-entry
- openSUSE-SU-2016:0307 vendor-advisory
- FEDORA-2015-51b1105902 vendor-advisory
- 1034426 vdb-entry