CVE-2026-68533: Concrete CMS below 9.5.3 conversation attachment uploaded endpoint imported files into the file manager before evaluating the "Add Message
Source GCVE Database
Not known to be exploited · CVSS 2.3 Low · fixed in 9.5.3 : update affected systems when convenient.
Data as of 31 Oct 2026, 08:20 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 33% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 9.5.3
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XExploitation evidence
Disclosed: evidence found.
CVE published 15 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
AI-suggested
A fix is available in Concrete CMS version 9.5.3 and later. Users should upgrade to version 9.5.3 or above to remediate this vulnerability. No other mitigation steps are indicated.
Description
Concrete CMS versions below 9.5.3 have a vulnerability in the conversation attachment upload endpoint where files are imported into the file manager before the system checks if the user has the "Add Message Attachments" permission. This permission check occurs only after the file is stored, allowing users without permission or unauthenticated visitors in guest-posting configurations to import approved file types into the file manager.