What is CVE-2021-20076?

CVE-2021-20076 is a high-severity vulnerability in Tenable Tenable.sc, classified under Deserialization of Untrusted Data. CVSS score: 8.8/10. Published 2021-03-03.

How severe is CVE-2021-20076?

High severity. CVSS v3 base score is 8.8 out of 10.

Deserialization in Tenable Tenable.sc

CVE-2021-20076

Tenable.sc and Tenable.sc Core versions 5.13.0 through 5.17.0 were found to contain a vulnerability that could allow an authenticated, unprivileged user to perform Remote Code Execution (RCE) on the Tenable.sc server via Hypertext Preprocessor unserialization.

Vulnerability class: Insecure Deserialization

Published 2021-03-03 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.021 (80.7th percentile), scored 2026-10-08.

Low probability of exploitation in the next 30 days, but still tracked. 81st percentile — 80.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.020 · newest: 0.021 · change: +0.001

Affected products

Tenable Tenable.sc
Tenable.sc — versions 5.13.0 through 5.17.0

Weakness classification (CWE)

CWE-502 — Deserialization of Untrusted Data

References

www.tenable.com/security/tns-2021-03 (Vendor Advisory)

Frequently asked questions

What is CVE-2021-20076?: CVE-2021-20076 is a high-severity vulnerability in Tenable Tenable.sc, classified under Deserialization of Untrusted Data. CVSS score: 8.8/10. Published 2021-03-03.
How severe is CVE-2021-20076?: High severity. CVSS v3 base score is 8.8 out of 10.