Auth bypass in Znuny

CVE-2025-26842

An issue was discovered in Znuny through 7.1.3. If access to a ticket is not given, the content of S/MIME encrypted e-mail messages is visible to users with access to the CommunicationLog.

Vulnerability class: Broken Access Control

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.003 (25.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 26th percentile — 25.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-26842: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-26842?
CVE-2025-26842 is a high-severity vulnerability in Znuny, classified under Incorrect Authorization. CVSS score: 7.5/10. Published 2025-05-08.
How severe is CVE-2025-26842?
High severity. CVSS v3 base score is 7.5 out of 10.