What is CVE-2021-22950?

CVE-2021-22950 is a medium-severity vulnerability in Concretecms Concrete Cms, classified under Cross-Site Request Forgery (CSRF). CVSS score: 6.5/10. Published 2021-09-23.

How severe is CVE-2021-22950?

Medium severity. CVSS v3 base score is 6.5 out of 10.

CSRF in Concretecms Concrete Cms

CVE-2021-22950

Concrete CMS prior to 8.5.6 had a CSFR vulnerability allowing attachments to comments in the conversation section to be deleted.Credit for discovery: "Solar Security Research Team"

Vulnerability class: CSRF (Cross-Site Request Forgery)

Published 2021-09-23 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.004 (36.2th percentile), scored 2026-10-07.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 36th percentile — 36.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Concretecms Concrete Cms
Https://github.com/concrete5/concrete5 — versions Fixed version 8.5.6

Weakness classification (CWE)

CWE-352 — Cross-Site Request Forgery (CSRF)

References

documentation.concretecms.org/developers/introduction/version-history/856-relea… (Release Notes)
hackerone.com/reports/1102177 (Permissions Required)

Frequently asked questions

What is CVE-2021-22950?: CVE-2021-22950 is a medium-severity vulnerability in Concretecms Concrete Cms, classified under Cross-Site Request Forgery (CSRF). CVSS score: 6.5/10. Published 2021-09-23.
How severe is CVE-2021-22950?: Medium severity. CVSS v3 base score is 6.5 out of 10.