vulnerability
MFSA2017-21 Firefox: Security vulnerabilities fixed in Firefox 56 (CVE-2017-7820)
| Severity | CVSS | Published | Added | Modified |
|---|---|---|---|---|
| 5 | (AV:N/AC:L/Au:N/C:N/I:P/A:N) | Jun 11, 2018 | Jul 12, 2018 | Mar 27, 2026 |
Severity
5
CVSS
(AV:N/AC:L/Au:N/C:N/I:P/A:N)
Published
Jun 11, 2018
Added
Jul 12, 2018
Modified
Mar 27, 2026
Description
The "instanceof" operator can bypass the Xray wrapper mechanism. When called on web content from the browser itself or an extension the web content can provide its own result for that operator, possibly tricking the browser or extension into mishandling the element. This vulnerability affects Firefox < 56.
Solution
mozilla-firefox-upgrade-56_0
Rapid7 Labs
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