Stored XSS Vulnerability in Concrete CMS by Concrete5
CVE-2026-8139

2LOW

Key Information:

Vendor

Concrete Cms

Status
Concrete Cms
Vendor
CVE Published:
21 May 2026

What is CVE-2026-8139?

Concrete CMS versions 9.5.0 and earlier are susceptible to a stored cross-site scripting (XSS) vulnerability through the external-link page 'cvName'. The flaw arises when the updateCollectionAliasExternal function fails to properly sanitize user input. This oversight allows malicious scripts to be stored and executed in the context of other users' sessions, potentially compromising user data and the overall integrity of the application. Users are urged to upgrade to a later version to mitigate this security risk.

Affected Version(s)

Concrete CMS 5.0 <= 9.5.0

References

https://documentation.concretecms.org/9-x/developers/intr...
release-notes

CVSS V4

Score:
2
Severity:
LOW
Confidentiality:
Low
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • Vulnerability published

  • Vulnerability Reserved

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