CVE-2021-32707: Nextcloud Mail

Medium severity, CVSS 4.3. EPSS: 1.1% chance of exploitation in the next 30 days.

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 exist.

Affected products

• Nextcloud Mail: before 1.9.6 (fixed in 1.9.6)

Published 2021-07-12. Last modified 2026-06-17.