Quick answer
Direct answer
Risk scores
| CVSS metric | What it means |
|---|---|
| Attack vector (AV:N) | Network: reachable remotely |
| Attack complexity (AC:L) | Low complexity |
| Privileges required (PR:L) | Low privileges required |
| User interaction (UI:N) | No user interaction |
| Scope (S:C) | Scope changed: impact spreads beyond the component |
| Confidentiality (C:L) | Low confidentiality impact |
| Integrity (I:H) | High integrity impact |
| Availability (A:N) | No availability impact |
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:N
About Monospace Directus
CVE-2026-39942 affects Monospace Directus, a product from Monospace. Before acting, confirm where Monospace Directus runs in your estate, who owns it and whether it is reachable from the internet, because exposure decides real risk more than the score alone.
What the flaw is
In plain terms: Directus is a real-time API and App dashboard for managing SQL database content. Prior to 11.17.0, the PATCH /files/{id} endpoint accepts a user-controlled filename_disk parameter. By setting this value to match the storage path of another user's file, an attacker can overwrite that file's content while manipulating metadata fields such as uploaded_by to obscure the tampering. This vulnerability is fixed in 11.17.0.
The weakness class is Improper Access Control. The software does not properly restrict who can use a resource.
Based on its CVSS vector, the flaw can be reached over the network, needs some level of access, and needs no user interaction. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.
Affected versions and timeline
| Field | Detail |
|---|---|
| Product | Monospace Directus |
| Affected versions | Directus before 11.17.0 |
| Published | Apr 9, 2026 |
| Last modified | Jun 17, 2026 |
| Added to CISA KEV | Not listed |
| Assigning CNA | security-advisories@github.com |
How to detect it
- Inventory every instance of Monospace Directus and record the running version against the affected range above.
- Check external attack surface scans for internet facing instances of the component.
- Review logs on affected systems for unusual requests, errors or new processes around the vulnerable function.
- Confirm with an authenticated vulnerability scan once your scanner has a check for this CVE.
How to fix it
- Apply the fixed version of Monospace Directus named in the vendor advisory.
- If patching must wait, restrict network access to the affected service and put it behind authentication or a web application firewall rule.
- Rescan after the change to prove the exposure is gone, then close the ticket.
CTEM action plan
| CTEM stage | What to do for this CVE |
|---|---|
| Scope | Add every business service that depends on Monospace Directus to the current CTEM cycle. |
| Discover | Find all instances, including shadow and cloud deployments, and record versions and exposure. |
| Prioritize | Rank using EPSS and CVSS together with asset exposure and business impact. |
| Validate | Confirm the flaw is reachable and exploitable in your environment and that compensating controls work. |
| Mobilize | Assign the fix to the asset owner with a due date matched to the priority, then verify closure. |
CWE References
- CWE-284: Improper Access Control More CVEs with this weakness
- CWE-639: Insecure Direct Object Reference More CVEs with this weakness
Technical References
Frequently asked questions
Related CVEs
Directus is a real-time API and App dashboard for managing SQL database content. Prior to 11.16.1, Directus' TUS resumable upload endpoint (/files/tus) allows any authenticated user with basic file upload permissions to overwrite arbitrary existing files by UUID. The TUS controller performs only collection-level authorization checks, verifying the user has some permission on directus_files, but never validates item-level access to the specific file being replaced. As a result, row-level permission rules (e.g., "users can only update their own files") are completely bypassed via the TUS path while being correctly enforced on the standard REST upload path. This vulnerability is fixed in 11.16.1.
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