What is CVE-2021-41921?

CVE-2021-41921 is a critical-severity vulnerability in Xxyopen Novel-Plus, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 9.8/10. Published 2022-04-28.

How severe is CVE-2021-41921?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Arbitrary file upload in Xxyopen Novel-Plus

CVE-2021-41921

novel-plus V3.6.1 allows unrestricted file uploads. Unrestricted file suffixes and contents can lead to server attacks and arbitrary code execution.

Vulnerability class: Unrestricted File Upload

Published 2022-04-28 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.017 (76.6th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 77th percentile — 76.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.016 · newest: 0.017 · change: +0.001

Affected products

Xxyopen Novel-Plus — versions 3.6.1

Weakness classification (CWE)

CWE-434 — Unrestricted Upload of File with Dangerous Type

References

github.com/201206030/novel-plus/issues/62 (Exploit, Third Party Advisory, Issue Tracking)

Frequently asked questions

What is CVE-2021-41921?: CVE-2021-41921 is a critical-severity vulnerability in Xxyopen Novel-Plus, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 9.8/10. Published 2022-04-28.
How severe is CVE-2021-41921?: Critical severity. CVSS v3 base score is 9.8 out of 10.