CVE-2020-12409

HIGH 8.8CVE-2020-12409 · Published 09/07/2020 · updated 17/06/2026

In short

CVE-2020-12409 is a HIGH (CVSS 8.8) vulnerability affecting firefox (mozilla).
Chance of exploitation in the next 30 days (EPSS): 1.2%, higher than 67.8% of all vulnerabilities.
Fix: update to 77.0 or later.

Package	Affected versions	Patched versions
firefox mozilla	`< 77.0`	`77.0`

Description

When using certain blank characters in a URL, they where incorrectly rendered as spaces instead of an encoded URL. This vulnerability affects Firefox < 77.

References

bugzilla.mozilla.org/show_bug.cgi · Issue Tracking
mozilla.org/security/advisories/mfsa2020-20 · Vendor Advisory

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Package

Affected versions

Patched versions

firefox

mozilla

< 77.0

77.0

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