CVE-2021-38497

Name: CVE-2021-38497
Creator: NVD / NIST
Published: 2021-11-03T01:15:07.427+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 0.53%

Last modified Jun 17, 2026

CVE-2021-38497 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. Through use of reportValidity() and window.open(), a plain-text validation message could have been overlaid on another origin, leading to possible user confusion and spoofing attacks. This vulnerability affects Firefox < 93, Thunderbird < 91.2, and Firefox ESR < 91.2.. EPSS estimates a 0.53% chance of exploitation in the next 30 days.

Description

Through use of reportValidity() and window.open(), a plain-text validation message could have been overlaid on another origin, leading to possible user confusion and spoofing attacks. This vulnerability affects Firefox < 93, Thunderbird < 91.2, and Firefox ESR < 91.2.

Metrics

CVSS 3.1

6.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

EPSS Probability

0.53%

40.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-346

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 93.0
Mozilla	Firefox Esr	< 91.2
Mozilla	Thunderbird	< 91.2

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1726621Permissions Required, Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2021-43/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2021-45/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2021-47/Vendor Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1726621Permissions Required, Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2021-43/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2021-45/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2021-47/Vendor Advisory

Timeline

Published: Nov 3, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-38497?

How severe is CVE-2021-38497?

CVE-2021-38497 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.53% probability of exploitation in the next 30 days.

How do I fix CVE-2021-38497?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-38497?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST