CVE-2021-43530

Name: CVE-2021-43530
Creator: NVD / NIST
Published: 2021-12-08T22:15:09.257+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10EPSS 1.39%

Last modified Jun 17, 2026

CVE-2021-43530 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. A Universal XSS vulnerability was present in Firefox for Android resulting from improper sanitization when processing a URL scanned from a QR code. *This bug only affects Firefox for Android. EPSS estimates a 1.39% chance of exploitation in the next 30 days.

Description

A Universal XSS vulnerability was present in Firefox for Android resulting from improper sanitization when processing a URL scanned from a QR code. *This bug only affects Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox < 94.

Metrics

CVSS 3.1

6.1/10

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

EPSS Probability

1.39%

68.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 94.0

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1736886Issue Tracking, Permissions Required
https://www.mozilla.org/security/advisories/mfsa2021-48/Vendor Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1736886Issue Tracking, Permissions Required
https://www.mozilla.org/security/advisories/mfsa2021-48/Vendor Advisory

Timeline

Published: Dec 8, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-43530?

How severe is CVE-2021-43530?

CVE-2021-43530 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 1.39% probability of exploitation in the next 30 days.

How do I fix CVE-2021-43530?

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-2021-43530?

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

Scan your code now

Source: NVD / NIST