What is CVE-2021-27558?

CVE-2021-27558 is a medium-severity vulnerability in Easycorp Zentao, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-08-31.

How severe is CVE-2021-27558?

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

XSS in Easycorp Zentao

CVE-2021-27558

A cross site scripting (XSS) issue in EasyCorp ZenTao 12.5.3 allows remote attackers to execute arbitrary web script via various areas such as data-link-creator.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2021-08-31 · 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: 0.008 (56.1th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 56th percentile — 56.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: 0.000

Affected products

Easycorp Zentao — versions 12.5.3

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

privasec.com/blog/zentao-cms-a-monkeys-journey-to-priv-esc-remote-code-executio… (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2021-27558?: CVE-2021-27558 is a medium-severity vulnerability in Easycorp Zentao, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-08-31.
How severe is CVE-2021-27558?: Medium severity. CVSS v3 base score is 6.1 out of 10.