CVE-2025-11655: Total.js Flow Unrestricted Upload Vulnerability

CVE-2025-11655 Overview

CVE-2025-11655 is an unrestricted file upload vulnerability in the SVG File Handler component of Total.js Flow. The flaw affects builds up to commit 673ef9144dd25d4f4fd4fdfda5af27f230198924. An authenticated remote attacker with high privileges can manipulate the handler to upload arbitrary SVG files. The weakness is classified under [CWE-284] Improper Access Control. Total.js Flow ships through continuous delivery with rolling releases, so no fixed version identifiers are published. The vendor was contacted about the issue but did not respond. Public exploit information has been released.

Critical Impact
An authenticated attacker can upload arbitrary SVG content remotely, potentially staging stored cross-site scripting or content-based attacks against Total.js Flow users.

Affected Products

Total.js Flow (rolling release up to commit 673ef9144dd25d4f4fd4fdfda5af27f230198924)
Component: SVG File Handler
No fixed version identifier due to continuous delivery model

Discovery Timeline

2025-10-13 - CVE-2025-11655 published to the National Vulnerability Database
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-11655

Vulnerability Analysis

The vulnerability resides in the SVG File Handler component of Total.js Flow. The handler accepts SVG uploads without adequate restriction on file content or origin. Because SVG files can embed scripting and external references, unrestricted upload creates a delivery channel for stored payloads served from the application's trusted origin. The issue is remotely reachable over the network but requires an authenticated session with elevated privileges, limiting the scope of untrusted callers. Impact is bounded to low-severity effects on confidentiality, integrity, and availability of resources served by the affected instance.

Root Cause

The root cause is improper access control on the SVG upload path [CWE-284]. The handler does not enforce sufficient validation or authorization on the content type, structure, or destination of uploaded files. Rolling delivery means the exact code path and its state at any given commit vary across deployments, complicating downstream tracking.

Attack Vector

An attacker with valid high-privilege credentials sends a crafted HTTP request to the SVG File Handler endpoint. The request contains an SVG file whose contents are outside the handler's expected input set. Because the handler does not restrict the upload, the file is stored and can be served back to other users of the Flow interface. No user interaction is required at upload time. Public exploit material referenced by VulDB entry #328072 describes the manipulation.

No verified proof-of-concept code is available. Refer to the VulDB technical entry for exploitation details.

Detection Methods for CVE-2025-11655

Indicators of Compromise

Unexpected SVG files stored in Total.js Flow upload directories or associated object storage
SVG payloads containing <script> elements, onload handlers, or external xlink:href references
Upload requests to the SVG File Handler originating from administrative accounts at unusual times or source IPs
Web server logs showing POST requests to Flow upload endpoints followed by GET requests retrieving newly stored SVGs

Detection Strategies

Inspect uploaded SVG content server-side for embedded scripts, foreign objects, and event handler attributes
Correlate authenticated Flow session activity with file upload events to identify anomalous privileged uploads
Baseline normal SVG upload volume per account and alert on deviations

Monitoring Recommendations

Enable verbose access logging on the Total.js Flow administrative interface
Forward web server, application, and file system telemetry to a centralized analytics platform for correlation
Monitor for outbound requests initiated when SVGs are rendered, which may indicate embedded external references
Track integrity of the upload directory using file integrity monitoring

How to Mitigate CVE-2025-11655

Immediate Actions Required

Restrict network access to the Total.js Flow administrative interface to trusted management networks
Audit and rotate credentials for all high-privilege Flow accounts to limit the pool of users who can trigger the flaw
Review existing SVG uploads and remove files that contain script or external reference elements
Serve stored SVGs with a restrictive Content-Security-Policy and Content-Disposition: attachment where feasible

Patch Information

No vendor patch is published. Total.js Flow uses continuous delivery, and the vendor did not respond to disclosure. Operators should track the upstream repository for post-disclosure commits addressing the SVG File Handler and apply the latest revision after validation in a staging environment. Reference the VulDB advisory for updates.

Workarounds

Disable the SVG File Handler if the deployment does not require SVG uploads
Place a reverse proxy or web application firewall in front of Flow to filter SVG uploads containing <script>, <foreignObject>, or event-handler attributes
Re-encode uploaded SVGs through a sanitizer such as DOMPurify or svg-sanitizer before persistence
Enforce multi-factor authentication on all administrator accounts to reduce the risk of credential-based abuse

bash

# Example nginx snippet to block SVG uploads at the reverse proxy
location /flow/upload {
    if ($request_method = POST) {
        if ($http_content_type ~* "image/svg\+xml") {
            return 403;
        }
    }
    proxy_pass http://flow_backend;
}