CVE-2021-38498

Name: CVE-2021-38498
Creator: NVD / NIST
Published: 2021-11-03T01:15:07.47+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 1.42%

Last modified Jun 17, 2026

CVE-2021-38498 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. During process shutdown, a document could have caused a use-after-free of a languages service object, leading to memory corruption and a potentially exploitable crash. This vulnerability affects Firefox < 93, Thunderbird < 91.2, and Firefox ESR < 91.2.. EPSS estimates a 1.42% chance of exploitation in the next 30 days.

Description

During process shutdown, a document could have caused a use-after-free of a languages service object, leading to memory corruption and a potentially exploitable crash. This vulnerability affects Firefox < 93, Thunderbird < 91.2, and Firefox ESR < 91.2.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

1.42%

69.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-416

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=1729642Permissions 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=1729642Permissions 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-2021-38498?

How severe is CVE-2021-38498?

CVE-2021-38498 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.42% probability of exploitation in the next 30 days.

How do I fix CVE-2021-38498?

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-2021-38498?

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

Scan your code now

Source: NVD / NIST