CVE-2026-8433
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedConcrete CMS 9 before 9.5.0 is vulnerable to Cross Site Request Forgery (CSRF) at concrete/controllers/backend/file rescan(). The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 2.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Yonatan Drori (Tenzai) for reporting.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceCSRF vulnerability in Concrete CMS 9 before 9.5.0 in the file rescan() function within concrete/controllers/backend/file. Attackers can trick authenticated administrators into unknowingly submitting malicious requests to rescan files, potentially modifying file metadata or triggering unintended file operations.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data>= 9.0.0, < 9.5.1CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check Concrete CMS versionLocate the version file in your Concrete CMS installation. Common locations include: the dashboard under 'Dashboard > System & Settings > About' or check the composer.json file in the web root for the 'concrete/cms' package version.Affected if The installed version is 9.0.0 or higher but lower than 9.5.1
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Verify the file rescan controller existsCheck if the file rescan controller exists at concrete/controllers/backend/file.php (or similar path) in your Concrete CMS installation directory. This is the vulnerable endpoint.Affected if The file rescan controller exists and is accessible without additional authentication beyond basic admin login
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Test for CSRF protection on the rescan endpointInspect the rescan() method in the file controller for presence of CSRF token validation. Look for code that validates tokens, typically using $this->validateCSRFToken() or similar methods before executing the rescan operation.Affected if The rescan() method lacks CSRF token validation or the validation is not properly enforced
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Check if file rescan is exposed to untrusted usersReview user permissions and access controls for the file rescan functionality. Determine if the endpoint is accessible to all administrators or if it can be triggered via crafted links by untrusted users.Affected if The file rescan endpoint can be triggered by authenticated administrators who may be tricked into unintended actions via cross-site requests
You are affected if your Concrete CMS version is 9.0.0 through 9.5.0 (inclusive) and the file rescan controller lacks proper CSRF token protection.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped9.5.1
Upgrade to Concrete CMS 9.5.0 or later which includes CSRF token validation for the file rescan endpoint. Alternatively, implement anti-CSRF tokens on the vulnerable endpoint.
Concrete CMS 9.5.1 or later
- 1. Backup the current Concrete CMS installation and database before making any changes
- 2. Download Concrete CMS version 9.5.1 or later from the official website (documentation.concretecms.org)
- 3. Follow the official Concrete CMS upgrade documentation to update from your current version
- 4. Clear any caches after upgrading
- 5. Verify the file rescan() functionality works correctly after the upgrade
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation1.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2026-8433 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-8433 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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