CVE-2021-32707: Nextcloud Mail is a mail app for Nextcloud

Q: How do I fix CVE-2021-32707?

mail: upgrade to 1.9.6. Exact commands for each OS are on this page.

Q: Is CVE-2021-32707 being exploited?

CVE-2021-32707 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2021-32707 affect?

CVE-2021-32707 affects mail. Severity is medium (CVSS 4.3). Nextcloud Mail is a mail app for Nextcloud. In versions prior to 1.9.6, the Nextcloud Mail application does not, by default, render images in emails to not leak the read state. The privacy filter failed to filter images with a `background-i

Q: How urgent is CVE-2021-32707?

Priority 37/100. Public exploit reference

Routine

MEDIUM 4.3UPGRADE

CVE-2021-32707 is a medium-severity flaw (CVSS 4.3) affecting mail. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Nextcloud Mail is a mail app for Nextcloud. In versions prior to 1.9.6, the Nextcloud Mail application does not, by default, render images in emails to not leak the read state. The privacy filter failed to filter images with a `background-image` CSS attribute. Note that the images were still passed through the Nextcloud image proxy, and thus there was no IP leakage. The issue was patched in version 1.9.6 and 1.10.0. No workarounds are known to ex

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	4.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	1.1% (top 33%)
CISA exploited list	No
Weakness	CWE-20, CWE-200
Published	2021-07-12
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: nextcloud

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-07-12 19:15 UTCPublished CVE record published
2026-06-17 03:53 UTCUpdated Record last modified

nextcloud mail UPGRADE

Affected: < 1.9.6

Fixed in: 1.9.6

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy mail || rpm -q mail || mail --version

2. UPGRADE to 1.9.6 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade mail

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade mail

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-32707?

mail: upgrade to 1.9.6. Exact commands for each OS are on this page.

Is CVE-2021-32707 being exploited?

CVE-2021-32707 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-32707 affect?

CVE-2021-32707 affects mail. Severity is medium (CVSS 4.3). Nextcloud Mail is a mail app for Nextcloud. In versions prior to 1.9.6, the Nextcloud Mail application does not, by default, render images in emails to not leak the read state. The privacy filter failed to filter images with a `background-i

How urgent is CVE-2021-32707?

Priority 37/100. Public exploit reference

Software pages

Nextcloud vulnerabilities

Related CVEs

CVE-2025-66514 LOW 3.5 UPGRADE Nextcloud Mail is the mail app for Nextcloud, a self-hosted productivity platform
CVE-2024-52509 LOW 3.5 UPGRADE Nextcloud Mail is the mail app for Nextcloud, a self-hosted productivity platform
CVE-2024-52508 HIGH 8.2 UPGRADE Nextcloud Mail is the mail app for Nextcloud, a self-hosted productivity platform
CVE-2023-48307 LOW 3.5 UPGRADE Nextcloud Mail is the mail app for Nextcloud, a self-hosted productivity platform
CVE-2023-45660 MEDIUM 4.3 UPGRADE Nextcloud mail is an email app for the Nextcloud home server platform

References

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