CVE-2021-39220

Name: CVE-2021-39220
Creator: NVD / NIST
Published: 2021-10-25T19:15:09.577+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

LOWCVSS 3.5/10EPSS 0.76%

Last modified Jun 17, 2026

CVE-2021-39220 is a low-severity vulnerability rated 3.5/10 on the CVSS scale. Nextcloud is an open-source, self-hosted productivity platform The Nextcloud Mail application prior to versions 1.10.4 and 1.11.0 does by default not render images in emails to not leak the read state or user IP. The privacy filter failed to filter images with a relative protocol. EPSS estimates a 0.76% chance of exploitation in the next 30 days.

Description

Nextcloud is an open-source, self-hosted productivity platform The Nextcloud Mail application prior to versions 1.10.4 and 1.11.0 does by default not render images in emails to not leak the read state or user IP. The privacy filter failed to filter images with a relative protocol. It is recommended that the Nextcloud Mail application is upgraded to 1.10.4 or 1.11.0. There are no known workarounds aside from upgrading.

Metrics

CVSS 3.1

3.5/10

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

EPSS Probability

0.76%

50.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Nextcloud	Mail	< 1.10.4

References

https://github.com/nextcloud/mail/pull/5470Patch, Third Party Advisory
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-6q9v-wm8r-rcv5Third Party Advisory
https://hackerone.com/reports/1308147Permissions Required
https://github.com/nextcloud/mail/pull/5470Patch, Third Party Advisory
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-6q9v-wm8r-rcv5Third Party Advisory
https://hackerone.com/reports/1308147Permissions Required

Timeline

Published: Oct 25, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-39220?

How severe is CVE-2021-39220?

CVE-2021-39220 has a CVSS score of 3.5/10 (LOW severity). The EPSS model estimates a 0.76% probability of exploitation in the next 30 days.

How do I fix CVE-2021-39220?

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-2021-39220?

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

Scan your code now

Source: NVD / NIST