Skip to content

← Actionable
Medium, CVSS 6.3

Concrete CMS is vulnerable to IDOR combined with a missing authentication gate

CVE-2026-8236GHSA-58c8-vvqw-cm7m

What to do

Vendor fix available. Upgrade each affected package to the fixed version on its release line (concrete5/concrete5 9.5.1), redeploy, then verify what is actually installed.

This page has no inventory attached, so it cannot say whether you are affected. A vendor fix is not proof that your deployment is fixed.

Affected packages

Sources

Severity and exploitation
Exploitation
No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.
CVSS 4.0
6.3 · CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N · score source
EPSS
  • CVE-2026-8236: 0.68% estimated exploitation activity in the next 30 days; percentile 52.25 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.
Source description

As published by the source; long descriptions are shortened.

Concrete CMS 9.5.0 and below is vulnerable to IDOR combined with a missing authentication gate. The endpoint /ccm/system/dialogs/file/usage/{fID} accepts an integer file ID in the URL and returns internal site structure data (page IDs, versions, URL paths) to anyone who sends a GET request.

Dates and revisions
Published by the source
Last modified by the source
Source last checked
  1. Revision 1 · created ·

    Published from ghsa record GHSA-58c8-vvqw-cm7m

Agent brief

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-8236

Advisory: Concrete CMS is vulnerable to IDOR combined with a missing authentication gate
IDs: CVE-2026-8236, GHSA-58c8-vvqw-cm7m
Record: https://patchnext.com/advisories/cve-2026-8236 (revision 1, source checked 26 Oct 2026, 14:49 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: concrete5/concrete5 9.5.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist concrete5/concrete5: affected < 9.5.1; fixed in 9.5.1

## Suggested inspection (read-only)
- Packagist concrete5/concrete5: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on concrete5/concrete5.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-58c8-vvqw-cm7m (GitHub-reviewed advisory GHSA-58c8-vvqw-cm7m lists affected ranges: Packagist concrete5/concrete5 >=0 <9.5.1)

Commands are suggestions: review each one before running it.

Loading voting…