high CVSS 8.8

CVE-2026-42605·PHP vulnerability

AzuraCast is a self-hosted, all-in-one web radio management suite. Prior to version 0.23.6, the currentDirectory request parameter in the Flow.js media upload endpoint (POST /api/station/{station_id}/files/upload) is not sanitized for path traversal sequences. When combined with a local filesystem storage backend (the default), an authenticated user with media management permissions can write arbitrary files outside the station's media storage directory, achieving remote code execution by writing a PHP webshell to the web root. This issue has been patched in version 0.23.6.

Severity
high
Software
PHP
Fixed in
0.23.6
Published
2026-05-09

Affected versions

Until: 0.23.6

Fixed in: 0.23.6

How to fix this CVE

Update AzuraCast to version 0.23.6 or later to patch a critical path traversal vulnerability in the media upload endpoint. The flaw allows authenticated users with media management permissions to bypass directory restrictions and upload malicious PHP files to arbitrary locations on the server, leading to remote code execution. Immediately apply this update to all instances running versions prior to 0.23.6.

sudo dnf check-update azuracast && sudo dnf upgrade azuracast

Defensia detects this vulnerability

What an exploitation attempt looks like

Sample log line indicative of exploitation attempts:

POST /api/station/[0-9]+/files/upload.*currentDirectory=.*(\.\./|/|[a-z]:\\).*Content-Type: multipart/form-data

WAF mitigation (if patching is not yet possible)

Add this rule to your WAF to block exploitation attempts while you schedule the patch. 

Block POST requests to /api/station/*/files/upload where the currentDirectory parameter contains path traversal sequences (../, ..\, absolute paths starting with / or drive letters). Implement strict input validation to ensure currentDirectory only contains alphanumeric characters, hyphens, and underscores.

How to check if you are affected

  1. Check your AzuraCast version by navigating to the admin panel → System Settings → About, or run: curl -s http://localhost:8080/api/admin/system/status | grep -i version
  2. Verify if the vulnerable endpoint is accessible by testing POST requests to /api/station/{station_id}/files/upload with a valid station ID and authentication token
  3. Search web server access logs for suspicious POST requests to the upload endpoint with currentDirectory parameters containing ../ or absolute paths: grep -E 'POST.*files/upload.*currentDirectory' /var/log/nginx/access.log
  4. Confirm the patch by running: curl -s http://localhost:8080/api/admin/system/status | grep -i version and verify it shows 0.23.6 or higher

FAQ

What is CVE-2026-42605?

This vulnerability is a path traversal flaw in AzuraCast's file upload API that fails to properly sanitize the currentDirectory parameter, allowing authenticated users to write files outside the designated media storage directory and execute arbitrary PHP code on the server.

Is CVE-2026-42605 being actively exploited?

No, this vulnerability is not listed in CISA's Known Exploited Vulnerabilities (KEV) catalog and no public exploit has been disclosed as of the advisory date.

What versions of AzuraCast are affected by CVE-2026-42605?

All versions of AzuraCast prior to 0.23.6 are vulnerable; the exact earliest affected version is unknown but the fix was confirmed in version 0.23.6.

How do I check if my server is vulnerable to CVE-2026-42605?

Run: curl -s http://localhost:8080/api/admin/system/status 2>/dev/null | grep -oP '"version":\s*"\K[^"]+' and compare the result to 0.23.6; if your version is lower, you are vulnerable.

Does Defensia detect CVE-2026-42605?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If AzuraCast is installed on a monitored server, CVE-2026-42605 will appear in your dashboard with remediation steps.

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References

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