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How CVE-2026-58589 Works
CVE-2026-58589 is a missing authorization vulnerability affecting the FlowDrop module for Drupal, which enables administrators to build and run AI-driven workflows through an interactive chat interface. The flaw stems from the module’s failure to sufficiently enforce permission checks on certain API endpoints, allowing attackers to bypass normal access controls via forceful browsing techniques.
When a user sends a request to a protected FlowDrop endpoint, the module does not consistently verify whether the requesting user possesses the required permissions (e.g., “View any session”). This means an attacker can craft direct HTTP requests to URLs that should only be accessible to privileged users, such as workflow execution triggers or session message endpoints. Because the authorization logic is incomplete, the server processes these requests without validating the user’s role or scope, effectively granting unauthorized access to sensitive functions.
The vulnerability affects all FlowDrop versions from 0.0.0 up to and including 1.6.0. It is classified under CWE-863 (Authorization Bypass Through User-Controlled Key) and maps to MITRE ATT&CK techniques T1078 (Valid Accounts) and T1566 (Phishing), as attackers may leverage legitimate but under-privileged accounts to escalate access.
From a technical standpoint, the module’s routing and controller logic lack proper `access` callbacks or permission checks on endpoints that handle workflow state transitions, message passing, and session management. This allows a remote, authenticated attacker (with at least basic Drupal user permissions) to:
– Trigger workflow executions, incurring LLM API costs and unintended tool side effects.
– Inject or replay messages into other users’ active sessions, potentially leading to cross‑session data leakage or manipulation.
The vulnerability is remotely exploitable over the network with low attack complexity and requires low privileges (authenticated user). It has a CVSS v4.0 base score of 5.3 (Medium) with the vector CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green. No public exploit is available as of the publication date, but the attack surface is broad because any authenticated user can attempt to access the vulnerable endpoints.
Drupal.org published security advisory SA-CONTRIB-2026-067 on July 1, 2026, addressing this issue. The fix was released in FlowDrop version 1.6.0, which adds proper permission checks to all affected endpoints. Administrators are strongly urged to update immediately, as leaving the module unpatched exposes the site to data breaches, unauthorized workflow execution, and session hijacking.
DailyCVE Form
| Field | Value |
|-|-|
| Platform | Drupal |
| Version | 0.0.0 – 1.6.0 |
| Vulnerability | Missing Authorization (Forceful Browsing) |
| Severity | Moderately critical (Medium) |
| Date | 2026-07-01 |
| Prediction | Patch already released (1.6.0) |
What Undercode Say: Analytics
- CVE ID : CVE-2026-58589
- Drupal Advisory : SA-CONTRIB-2026-067
- CWE : CWE-863 (Authorization Bypass Through User-Controlled Key)
- CVSS v4.0 : 5.3 (Medium) – `AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green`
– Attack Vector : Remote - Privileges Required : Low (authenticated user)
- Exploit Availability : No public exploit
- Affected Versions : 0.0.0 – 1.6.0
- Patched Version : 1.6.0
Bash Commands to Check & Mitigate
Check current FlowDrop version via Composer composer show drupal/flowdrop Alternatively, check via Drush drush pm:list --type=module --status=enabled | grep flowdrop Upgrade to the patched version (1.6.0 or later) composer require drupal/flowdrop:^1.6.0 Clear Drupal caches after update drush cr
How Exploit Works
- Identify Target Endpoint – The attacker discovers a vulnerable FlowDrop endpoint, e.g., `/flowdrop/execute/{workflow_id}` or
/flowdrop/session/{sid}/message, that lacks proper permission checks. - Craft Request – With a valid Drupal session cookie (authenticated as a low‑privilege user), the attacker sends a direct GET or POST request to that endpoint, including parameters like workflow ID or session ID.
- Bypass Authorization – The module processes the request without verifying if the user has the “View any session” or “Administer FlowDrop workflows” permission, allowing the attacker to:
– Execute arbitrary workflows (incurring LLM costs and side effects).
– Inject messages into other users’ chat sessions.
4. Achieve Unauthorized Access – The attacker gains the ability to perform actions that should be restricted to administrators or specific roles, leading to data exposure, resource abuse, or session takeover.
Protection from CVE-2026-58589
- Immediate Upgrade – Update FlowDrop to version 1.6.0 or later, which enforces proper permission checks on all affected endpoints.
- Apply Security Advisory – Follow the guidance in Drupal SA-CONTRIB-2026-067.
- Review Permissions – Ensure that the “View any session” permission is not granted to untrusted roles (it is disabled by default for anonymous and authenticated users).
- Monitor Logs – Audit Drupal watchdog logs for unusual workflow execution or session message activities.
- Network Controls – If immediate patching is not possible, consider using a Web Application Firewall (WAF) to block requests to known FlowDrop endpoints from untrusted IPs.
- Code Review – For custom modules that extend FlowDrop, verify that all controllers include appropriate `access` callbacks.
Impact
- Confidentiality – Attackers can read messages and session data belonging to other users, leading to information disclosure.
- Integrity – Unauthorized workflow execution can modify content or trigger unintended actions, potentially altering application state.
- Availability – Repeated workflow triggers may exhaust LLM API quotas or degrade performance, causing denial of service.
- Financial Loss – Unauthorized LLM usage incurs unexpected costs for the organization.
- Privilege Escalation – Although limited, the vulnerability can be chained with other flaws to gain higher privileges or persist within the system.
- Compliance – Data breaches may violate GDPR, HIPAA, or other regulatory requirements, exposing the organization to legal and reputational damage.
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Sources:
Reported By: nvd.nist.gov
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