CVE-2017-7820

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.

• http://www.securityfocus.com/bid/101057Third Party Advisory, VDB Entry
• http://www.securitytracker.com/id/1039465Third Party Advisory, VDB Entry
• https://bugzilla.mozilla.org/show_bug.cgi?id=1378207Exploit, Issue Tracking
• https://www.mozilla.org/security/advisories/mfsa2017-21/Vendor Advisory
• http://www.securityfocus.com/bid/101057Third Party Advisory, VDB Entry
• http://www.securitytracker.com/id/1039465Third Party Advisory, VDB Entry
• https://bugzilla.mozilla.org/show_bug.cgi?id=1378207Exploit, Issue Tracking
• https://www.mozilla.org/security/advisories/mfsa2017-21/Vendor Advisory

Published

Jun 11, 2018

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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