XSS in Mozilla Firefox

CVE-2019-11744

Some HTML elements, such as &lt;title&gt; and &lt;textarea&gt;, can contain literal angle brackets without treating them as markup. It is possible to pass a literal closing tag to .innerHTML on these elements, and subsequent content after that will be parsed as if it were outside the tag. This can lead to XSS if a site does not filter user input as strictly for these elements as it does for other elements. This vulnerability affects Firefox < 69, Thunderbird < 68.1, Thunderbird < 60.9, Firefox ESR < 60.9, and Firefox ESR < 68.1.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.015 (70.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2019-11744?
CVE-2019-11744 is a medium-severity vulnerability in Mozilla Firefox, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2019-09-27.
How severe is CVE-2019-11744?
Medium severity. CVSS v3 base score is 6.1 out of 10.