CVE-2020-6808

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-03-25 · updated 2026-06-17
Weakness: CWE-290

Description

When a JavaScript URL (javascript:) is evaluated and the result is a string, this string is parsed to create an HTML document, which is then presented. Previously, this document's URL (as reported by the document.location property, for example) was the originating javascript: URL which could lead to spoofing attacks; it is now correctly the URL of the originating document. This vulnerability affects Firefox < 74.

Affected products

Mozilla Firefox: before 74.0 — fixed in 74.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 74.0. Check the vendor advisory for mitigations.

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1247968
https://www.mozilla.org/security/advisories/mfsa2020-08/
https://bugzilla.mozilla.org/show_bug.cgi?id=1247968
https://www.mozilla.org/security/advisories/mfsa2020-08/

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