CVE-2026-50755: next-ai-draw-io Information Disclosure

CVE-2026-50755 Overview

CVE-2026-50755 affects DayuanJiang next-ai-draw-io version 0.4.13, an AI-assisted diagramming application. The vulnerability allows a remote attacker to obtain sensitive information by manipulating the X-Forwarded-For HTTP header value. The flaw maps to [CWE-290], Authentication Bypass by Spoofing, where the application trusts a client-controlled header to make trust or identity decisions.

Critical Impact
Remote unauthenticated attackers can spoof the X-Forwarded-For header to bypass source-based trust checks and access sensitive information exposed by the application.

Affected Products

DayuanJiang next-ai-draw-io version 0.4.13
Deployments exposing the application directly to untrusted networks
Instances behind reverse proxies that forward client-supplied X-Forwarded-For values without sanitization

Discovery Timeline

2026-07-21 - CVE-2026-50755 published to NVD
2026-07-22 - Last updated in NVD database

Technical Details for CVE-2026-50755

Vulnerability Analysis

The vulnerability resides in how next-ai-draw-io 0.4.13 processes the X-Forwarded-For HTTP request header. The application treats the header value as an authoritative indicator of the client's source address. An attacker who controls the header can present an arbitrary IP address to the application. This defeats any source-based restriction the application uses to gate access to sensitive information.

Because the attack is network-based, requires no authentication, and involves no user interaction, exploitation reduces to sending a crafted HTTP request. The vulnerability aligns with the [CWE-290] pattern where identity is inferred from spoofable inputs. The EPSS probability is 0.425% at the 34.79 percentile as of 2026-07-23.

Root Cause

The root cause is improper trust in a client-supplied HTTP header. The X-Forwarded-For header is set by clients and intermediate proxies and is not authenticated. Applications that use it to identify internal callers, whitelist localhost, or make authorization decisions can be tricked by injecting values such as 127.0.0.1 or an internal CIDR range.

Attack Vector

An attacker sends an HTTP request to an exposed next-ai-draw-io endpoint and adds X-Forwarded-For: 127.0.0.1 (or another trusted value) to the request. The application evaluates the header, treats the request as originating from a trusted source, and returns sensitive information that should be restricted. No credentials, tokens, or prior session state are required.

Technical details are available in the GitHub CVE-2026-50755 Document and the GitHub Issue #750 Discussion.

Detection Methods for CVE-2026-50755

Indicators of Compromise

Inbound HTTP requests to next-ai-draw-io endpoints containing X-Forwarded-For values referencing loopback (127.0.0.1), link-local, or RFC1918 addresses from external sources
Repeated requests from a single external IP that vary only the X-Forwarded-For header value
Access to administrative or diagnostic endpoints without a corresponding authenticated session

Detection Strategies

Inspect web server and reverse proxy access logs for external requests presenting internal or loopback addresses in X-Forwarded-For
Correlate the real TCP source IP with the header value and alert on mismatches to trusted ranges
Deploy WAF signatures that flag X-Forwarded-For values containing 127.0.0.1, ::1, or RFC1918 space when the connection originates from the public internet

Monitoring Recommendations

Enable verbose HTTP request header logging on the reverse proxy fronting next-ai-draw-io
Alert on any 200-response access to sensitive endpoints where the request lacked an authenticated identity
Track outbound data volume from the application to detect bulk information disclosure

How to Mitigate CVE-2026-50755

Immediate Actions Required

Restrict network exposure of next-ai-draw-io 0.4.13 to trusted networks or place it behind an authenticating reverse proxy
Configure upstream proxies to strip or overwrite the X-Forwarded-For header from external clients
Review application logs for prior requests containing spoofed header values and assess data exposure

Patch Information

No fixed version is listed in the NVD entry at the time of publication. Monitor the GitHub Issue #750 Discussion and the project repository for a patched release. Upgrade as soon as a fixed version is available.

Workarounds

Terminate all client connections at a reverse proxy such as Nginx or HAProxy and rewrite X-Forwarded-For to reflect only the true remote address
Do not rely on X-Forwarded-For for authorization; require authentication for any endpoint returning sensitive information
Block direct network access to the application port and only permit traffic from the proxy tier

bash

# Nginx example: overwrite client-supplied X-Forwarded-For
location / {
    proxy_set_header X-Forwarded-For $remote_addr;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_pass http://next_ai_draw_io_upstream;
}