CVE-2020-12391
Mozilla: Content-Security-Policy bypass using object elements
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · May 5, 2020
Updated · January 8, 2026
Description
The Mozilla Foundation Security Advisory describes this flaw as:
Documents formed using data: URLs in an object element failed to inherit the CSP of the creating context. This allowed the execution of scripts that should have been blocked, albeit with a unique opaque origin.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.1 · 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CWE-358 · Improperly Implemented Security Check for Standard