CVE-2023-5721

Name: CVE-2023-5721
Creator: NVD / NIST
Published: 2023-10-25T18:17:43.98+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 4.3/10EPSS 0.78%

Last modified Jun 17, 2026

CVE-2023-5721 is a medium-severity vulnerability rated 4.3/10 on the CVSS scale. It was possible for certain browser prompts and dialogs to be activated or dismissed unintentionally by the user due to an insufficient activation-delay. This vulnerability affects Firefox < 119, Firefox ESR < 115.4, and Thunderbird < 115.4.1.. EPSS estimates a 0.78% chance of exploitation in the next 30 days.

Description

It was possible for certain browser prompts and dialogs to be activated or dismissed unintentionally by the user due to an insufficient activation-delay. This vulnerability affects Firefox < 119, Firefox ESR < 115.4, and Thunderbird < 115.4.1.

Metrics

CVSS 3.1

4.3/10

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

EPSS Probability

0.78%

51.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-1021

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 119.0
Mozilla	Firefox Esr	< 115.4
Mozilla	Thunderbird	< 115.4.1
Debian	Debian Linux	10.0
Debian	Debian Linux	11.0

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1830820Issue Tracking, Vendor Advisory
https://lists.debian.org/debian-lts-announce/2023/10/msg00037.htmlMailing List, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2023/10/msg00042.htmlMailing List, Third Party Advisory
https://www.debian.org/security/2023/dsa-5535Mailing List, Third Party Advisory
https://www.debian.org/security/2023/dsa-5538Third Party Advisory
https://www.mozilla.org/security/advisories/mfsa2023-45/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2023-46/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2023-47/Vendor Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1830820Issue Tracking, Vendor Advisory
https://lists.debian.org/debian-lts-announce/2023/10/msg00037.htmlMailing List, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2023/10/msg00042.htmlMailing List, Third Party Advisory
https://www.debian.org/security/2023/dsa-5535Mailing List, Third Party Advisory
https://www.debian.org/security/2023/dsa-5538Third Party Advisory
https://www.mozilla.org/security/advisories/mfsa2023-45/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2023-46/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2023-47/Vendor Advisory

Timeline

Published: Oct 25, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-5721?

How severe is CVE-2023-5721?

CVE-2023-5721 has a CVSS score of 4.3/10 (MEDIUM severity). The EPSS model estimates a 0.78% probability of exploitation in the next 30 days.

How do I fix CVE-2023-5721?

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-2023-5721?

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

Scan your code now

Source: NVD / NIST