CVSS 3.0
5.3 mediumCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:NCVE-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.
Severity
- EPSS
- 1.2% chance of exploitation in the next 30 days; higher than 67% of CVEs (scores of 2026-10-31)
- Published
- Modified
- Record from
- the NVD, synced
Affected
- mozilla:firefox