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Vulnerability · Published Sep 15, 2026 · Assigned by ConcreteCMS

CVE-2026-68533Missing Authorization in Concrete CMS versions below 9.5.3 Conversation File Upload Allows File Import Without the Add Message Attachments Permission

Low 2.3

In plain English

A low-severity missing authorization in Concrete CMS from Concrete CMS. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 34% of all known vulnerabilities).

Severity (CVSS 4.0)2.3Low
Exploit odds (30 days)0.4%top 66.3% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

Concrete CMS below 9.5.3 conversation attachment uploaded endpoint imported files into the file manager before evaluating the "Add Message Attachments" permission, which was only checked after the file had been stored. A user denied that permission, or an unauthenticated visitor on a guest-posting configuration, could import approved files of allowed types into the file manager. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 2.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N. Thanks riodrwn for reporting.

Affected products (as reported)

VendorProductVersions
Concrete CMS Concrete CMS 5.0.0 – through 9.5.2

Weakness: CWE-862 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N

References