CVE-2021-40110

Name: CVE-2021-40110
Creator: NVD / NIST
Published: 2022-01-04T09:15:07.327+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 2.86%

Last modified Jun 17, 2026

CVE-2021-40110 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. In Apache James, using Jazzer fuzzer, we identified that an IMAP user can craft IMAP LIST commands to orchestrate a Denial Of Service using a vulnerable Regular expression. This affected Apache James prior to 3.6.1 We recommend upgrading to Apache James 3.6.1 or higher , which enforce the use of RE2J regular expression engine to execute regex in linear time without back-tracking.. EPSS estimates a 2.86% chance of exploitation in the next 30 days.

Description

In Apache James, using Jazzer fuzzer, we identified that an IMAP user can craft IMAP LIST commands to orchestrate a Denial Of Service using a vulnerable Regular expression. This affected Apache James prior to 3.6.1 We recommend upgrading to Apache James 3.6.1 or higher , which enforce the use of RE2J regular expression engine to execute regex in linear time without back-tracking.

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

2.86%

85.0th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Apache	James	< 3.6.1

References

http://www.openwall.com/lists/oss-security/2022/01/04/2Mailing List, Third Party Advisory
https://www.openwall.com/lists/oss-security/2022/01/04/2Mailing List, Third Party Advisory
http://www.openwall.com/lists/oss-security/2022/01/04/2Mailing List, Third Party Advisory
https://www.openwall.com/lists/oss-security/2022/01/04/2Mailing List, Third Party Advisory

Timeline

Published: Jan 4, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-40110?

How severe is CVE-2021-40110?

CVE-2021-40110 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 2.86% probability of exploitation in the next 30 days.

How do I fix CVE-2021-40110?

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-2021-40110?

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

Scan your code now

Source: NVD / NIST