What is CVE-2021-40658?

CVE-2021-40658 is a medium-severity vulnerability in Textpattern, classified under Cross-site Scripting. CVSS score: 4.8/10. Published 2022-06-14.

How severe is CVE-2021-40658?

Medium severity. CVSS v3 base score is 4.8 out of 10.

XSS in Textpattern

CVE-2021-40658

Textpattern 4.8.7 is affected by a HTML injection vulnerability through “Content>Write>Body”.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2022-06-14 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.006 (45.8th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 46th percentile — 45.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Affected products

Textpattern — versions 4.8.7

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

tanmay26.medium.com/textpattern-4-8-7-is-affected-by-html-injection-in-the-body… (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2021-40658?: CVE-2021-40658 is a medium-severity vulnerability in Textpattern, classified under Cross-site Scripting. CVSS score: 4.8/10. Published 2022-06-14.
How severe is CVE-2021-40658?: Medium severity. CVSS v3 base score is 4.8 out of 10.