CVE-2021-33038

Name: CVE-2021-33038
Creator: NVD / NIST
Published: 2021-05-26T14:15:08.913+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 1.85%

Last modified Jun 17, 2026

CVE-2021-33038 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. An issue was discovered in management/commands/hyperkitty_import.py in HyperKitty through 1.3.4. When importing a private mailing list's archives, these archives are publicly visible for the duration of the import. EPSS estimates a 1.85% chance of exploitation in the next 30 days.

Description

An issue was discovered in management/commands/hyperkitty_import.py in HyperKitty through 1.3.4. When importing a private mailing list's archives, these archives are publicly visible for the duration of the import. For example, sensitive information might be available on the web for an hour during a large migration from Mailman 2 to Mailman 3.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

1.85%

76.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-276

Affected Software

Vendor	Product	Versions
Hyperkitty Project	Hyperkitty	<= 1.3.4
Debian	Debian Linux	10.0

References

https://gitlab.com/mailman/hyperkitty/-/commit/9025324597d60b2dff740e49b70b15589d6804faPatch, Third Party Advisory
https://gitlab.com/mailman/hyperkitty/-/issues/380Exploit, Issue Tracking, Patch, Third Party Advisory
https://techblog.wikimedia.org/2021/06/11/discovering-and-fixing-cve-2021-33038-in-mailman3/Patch, Third Party Advisory
https://www.debian.org/security/2021/dsa-4922Third Party Advisory
https://gitlab.com/mailman/hyperkitty/-/commit/9025324597d60b2dff740e49b70b15589d6804faPatch, Third Party Advisory
https://gitlab.com/mailman/hyperkitty/-/issues/380Exploit, Issue Tracking, Patch, Third Party Advisory
https://techblog.wikimedia.org/2021/06/11/discovering-and-fixing-cve-2021-33038-in-mailman3/Patch, Third Party Advisory
https://www.debian.org/security/2021/dsa-4922Third Party Advisory

Timeline

Published: May 26, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-33038?

How severe is CVE-2021-33038?

CVE-2021-33038 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.85% probability of exploitation in the next 30 days.

How do I fix CVE-2021-33038?

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-2021-33038?

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

Scan your code now

Source: NVD / NIST