Is CVE-2026-8432 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-8432 being exploited in the wild.

How severe is CVE-2026-8432?

Medium severity, with a CVSS score of 4, published 21 May 2026.

Which products and versions are affected?

Concrete CMS 9.0.0RC1 through 9.5.0; concrete5/concrete5 (Packagist) >= 9.0.0RC1, < 9.5.1, ECOSYSTEM:introduced=9.0.0RC1,fixed=9.5.1.

Is there a fix for CVE-2026-8432?

Yes. concrete5/concrete5 (Packagist): upgrade to 9.5.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-8432 attacked?

It is attacked over the network, in a web application.

Am I affected by CVE-2026-8432?

Check whether you run Concrete CMS or concrete5/concrete5 (Packagist) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-8432: Concrete CMS CSRF in file star controller

Q: Is there a fix for CVE-2026-8432?

Yes. concrete5/concrete5 (Packagist): upgrade to 9.5.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-8432 attacked?

It is attacked over the network, in a web application.

Q: Am I affected by CVE-2026-8432?

Check whether you run Concrete CMS or concrete5/concrete5 (Packagist) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-8432 · Severity: medium · CVSS 4 · Published 2026-05-21

Concrete CMS, a popular web content management system, is vulnerable to a security flaw that could allow an attacker to trick an administrator into performing unintended actions. Specifically, an attacker could cause a user to 'star' or favorite files without their consent by luring them to a malicious website while they are logged into the CMS. While this particular issue has a low impact on data security, it represents a breakdown in the application's request verification mechanisms.

Technologies: Concrete CMS, concrete5/concrete5 (Packagist). Vendors: Concrete CMS, Packagist.

Quick answers

Is CVE-2026-8432 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-8432 being exploited in the wild.
How severe is CVE-2026-8432?: Medium severity, with a CVSS score of 4, published 21 May 2026.
Which products and versions are affected?: Concrete CMS 9.0.0RC1 through 9.5.0; concrete5/concrete5 (Packagist) >= 9.0.0RC1, < 9.5.1, ECOSYSTEM:introduced=9.0.0RC1,fixed=9.5.1.
Is there a fix for CVE-2026-8432?: Yes. concrete5/concrete5 (Packagist): upgrade to 9.5.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-8432 attacked?: It is attacked over the network, in a web application.
Am I affected by CVE-2026-8432?: Check whether you run Concrete CMS or concrete5/concrete5 (Packagist) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

concrete5/concrete5 (Packagist): upgrade to 9.5.1 or later
```
composer require concrete5/concrete5:^9.5.1
```

Technical details

A Cross-Site Request Forgery (CSRF) vulnerability exists in Concrete CMS versions 9.0.0RC1 through 9.5.0 within the 'star' method of the file backend controller (concrete/controllers/backend/file). The application fails to properly validate CSRF tokens for requests to this endpoint. An attacker can exploit this by crafting a malicious webpage that, when visited by an authenticated user, submits a background request to the vulnerable CMS instance. This allows the attacker to programmatically toggle the 'starred' status of files on behalf of the victim. The vulnerability is addressed in version 9.5.1.

Affected products

Concrete CMS Concrete CMS 9.0.0RC1 through 9.5.0

Identifiers

CVE-2026-8432
GHSA-97jw-gr4m-c5v8

Timeline

2026-05-21: disclosed: NVD publication date
2026-05-22: advisory: GitHub Advisory published
2026-06-24: patched: Advisory updated with patch information

References

https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes

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