Description
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.
References (3)
Core 3
Core References
Third Party Advisory x_refsource_confirm
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-xxp4-44xc-8crh
Patch, Third Party Advisory x_refsource_misc
https://github.com/nextcloud/mail/pull/5189
Exploit, Third Party Advisory x_refsource_misc
https://hackerone.com/reports/1215251
Scores
CVSS v3
4.3
EPSS
0.0032
EPSS Percentile
55.4%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Details
CWE
CWE-20
CWE-200
Status
published
Products (1)
nextcloud/mail
< 1.9.6
Published
Jul 12, 2021
Tracked Since
Feb 18, 2026