What is CVE-2021-23936?

CVE-2021-23936 is a medium-severity vulnerability in Open-Xchange Appsuite, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-01-12.

How severe is CVE-2021-23936?

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

Is CVE-2021-23936 known to be exploited?

2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

XSS in Open-Xchange Appsuite

CVE-2021-23936

OX App Suite through 7.10.4 allows XSS via the subject of a task.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2021-01-12 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.009 (58.8th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 59th percentile — 58.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000

Affected products

Open-Xchange Appsuite

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

Public proof-of-concept exploits

References

packetstormsecurity.com/files/160853/OX-App-Suite-OX-Documents-7.10.x-XSS-SSRF… (VDB Entry, Third Party Advisory, Not Applicable)

Frequently asked questions

What is CVE-2021-23936?: CVE-2021-23936 is a medium-severity vulnerability in Open-Xchange Appsuite, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-01-12.
How severe is CVE-2021-23936?: Medium severity. CVSS v3 base score is 6.1 out of 10.
Is CVE-2021-23936 known to be exploited?: 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.