CVE-2020-12409

HIGH

Firefox < 77.0 - URL Spoofing via Blank Character Rendering

Title source: llm
STIX 2.1

Description

When using certain blank characters in a URL, they where incorrectly rendered as spaces instead of an encoded URL. This vulnerability affects Firefox < 77.

References (2)

Core 2
Core References
Issue Tracking, Permissions Required, Vendor Advisory x_refsource_misc
https://bugzilla.mozilla.org/show_bug.cgi?id=1629506

Scores

CVSS v3 8.8
EPSS 0.0023
EPSS Percentile 46.2%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Details

Status published
Products (1)
mozilla/firefox < 77.0
Published Jul 09, 2020
Tracked Since Feb 18, 2026