XSS in Mozilla Firefox

CVE-2020-6798

If a template tag was used in a select tag, the parser could be confused and allow JavaScript parsing and execution when it should not be allowed. A site that relied on the browser behaving correctly could suffer a cross-site scripting vulnerability as a result. In general, this flaw cannot be exploited through email in the Thunderbird product because scripting is disabled when reading mail, but is potentially a risk in browser or browser-like contexts. This vulnerability affects Thunderbird < 68.5, Firefox < 73, and Firefox < ESR68.5.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.021 (79.3th 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)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2020-6798?
CVE-2020-6798 is a medium-severity vulnerability in Mozilla Firefox, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2020-03-02.
How severe is CVE-2020-6798?
Medium severity. CVSS v3 base score is 6.1 out of 10.
Is CVE-2020-6798 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.