CVE-2024-9398

Name: CVE-2024-9398
Creator: NVD / NIST
Published: 2024-10-01T16:15:10.913+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.3/10EPSS 0.58%

Last modified Jun 17, 2026

CVE-2024-9398 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. By checking the result of calls to `window.open` with specifically set protocol handlers, an attacker could determine if the application which implements that protocol handler is installed. This vulnerability affects Firefox < 131, Firefox ESR < 128.3, Thunderbird < 128.3, and Thunderbird < 131.. EPSS estimates a 0.58% chance of exploitation in the next 30 days.

Description

By checking the result of calls to `window.open` with specifically set protocol handlers, an attacker could determine if the application which implements that protocol handler is installed. This vulnerability affects Firefox < 131, Firefox ESR < 128.3, Thunderbird < 128.3, and Thunderbird < 131.

Metrics

CVSS 3.1

5.3/10

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

EPSS Probability

0.58%

43.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-203

Affected Software

Vendor	Product	Versions	Update
Mozilla	Firefox	< 131.0	—
Mozilla	Firefox Esr	< 128.3.0	—
Mozilla	Thunderbird	< 128.3	—
Mozilla	Thunderbird	129.0	Beta

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1881037Issue Tracking, Permissions Required
https://www.mozilla.org/security/advisories/mfsa2024-46/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2024-47/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2024-49/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2024-50/Vendor Advisory

Timeline

Published: Oct 1, 2024
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2024-9398?

How severe is CVE-2024-9398?

CVE-2024-9398 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 0.58% probability of exploitation in the next 30 days.

How do I fix CVE-2024-9398?

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-2024-9398?

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

Scan your code now

Source: NVD / NIST