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Vulnerability record · CVE-2021-40102 · published 24 September 2021

CVE-2021-40102: Concretecms concrete cms deserialization of untrusted data vulnerability

Concretecms · Concrete Cms

An issue was discovered in Concrete CMS through 8.5.5. Arbitrary File deletion can occur via PHAR deserialization in is_dir (PHP Object Injection associated with the __wakeup magic method).

9.1 CVSS 3.1 Critical EPSS 1.3% · top 29.7% CWE-502 · Deserialization of untrusted data
9.1CVSS 3.1 base score, v2 6.4
1.3%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
4References
17 Jun 2026Last modified by NVD

Description

An issue was discovered in Concrete CMS through 8.5.5. Arbitrary File deletion can occur via PHAR deserialization in is_dir (PHP Object Injection associated with the __wakeup magic method).

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://documentation.concretecms.org/developers/introduction/version-history/856-release-notes Release NotesVendor Advisory
https://hackerone.com/reports/921288 Permissions RequiredThird Party Advisory
https://documentation.concretecms.org/developers/introduction/version-history/856-release-notes Release NotesVendor Advisory
https://hackerone.com/reports/921288 Permissions RequiredThird Party Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2021-40102), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.