What is CVE-2016-4026?

CVE-2016-4026 is a medium-severity vulnerability in Open-Xchange Appsuite, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2016-12-15.

How severe is CVE-2016-4026?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XSS in Open-Xchange Appsuite

CVE-2016-4026

An issue was discovered in Open-Xchange OX App Suite before 7.8.1-rev11. The content sanitizer component has an issue with filtering malicious content in case invalid HTML code is provided. In such cases the filter will output a unsanitized representation of the content. Malicious script code can be executed within a user's context. This can lead to session hijacking or triggering unwanted actions via the web interface (sending mail, deleting data etc.). Attackers can use this issue for filter evasion to inject script code later on.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2016-12-15 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.007 (51.9th percentile), scored 2026-10-02.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 52nd percentile — 51.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000

Affected products

Open-Xchange Appsuite

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

www.securitytracker.com/id/1036157 (VDB Entry, Third Party Advisory, vdb-entry)
www.securityfocus.com/archive/1/538732/100/0/threaded (mailing-list)

Frequently asked questions

What is CVE-2016-4026?: CVE-2016-4026 is a medium-severity vulnerability in Open-Xchange Appsuite, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2016-12-15.
How severe is CVE-2016-4026?: Medium severity. CVSS v3 base score is 6.1 out of 10.