CVE-2026-71801: SPMS-Server Authentication Bypass Vulnerability

CVE-2026-71801 Overview

CVE-2026-71801 affects s-pms SPMS-Server through v1.0. The application ships with a hardcoded default access token secret inside its core configuration file. The production environment profile does not override or remove this secret. A remote, unauthenticated attacker can use the known secret to forge valid administrative session tokens locally. The forged tokens bypass the authentication mechanism entirely and grant full unauthorized access to protected backend APIs. The flaw maps to hardcoded credentials weaknesses commonly cataloged under [CWE-798].

Critical Impact

An unauthenticated remote attacker can forge administrative session tokens and gain full access to backend APIs without any valid credentials.

Affected Products

• s-pms SPMS-Server through version v1.0

Discovery Timeline

• 2026-09-09 - CVE-2026-71801 published to the National Vulnerability Database (NVD)
• 2026-09-09 - Last updated in NVD database

Technical Details for CVE-2026-71801

Vulnerability Analysis

SPMS-Server uses a token-based authentication scheme. Session tokens are signed with a secret defined in the core configuration file. That secret is hardcoded and shipped with the application. The production profile inherits the same value rather than overriding it with an environment-specific secret.

Any party in possession of the source code or the packaged application knows the signing secret. That party can generate tokens that the server will accept as valid. The server treats forged administrative tokens as legitimate sessions and grants access to protected endpoints.

The practical result is a complete authentication bypass against administrative APIs. No credential guessing, brute force, or network-side interception is required.

Root Cause

The root cause is a hardcoded default access token secret embedded in the core configuration file. Secrets used to sign authentication tokens must be unique per deployment and generated at install time. Here the secret is static across every installation and is present in publicly available source. This is a hardcoded credentials weakness combined with an insecure default configuration.

Attack Vector

An attacker retrieves the hardcoded secret from the SPMS-Server source or a distributed build. Using standard token libraries, the attacker signs an administrative session token with the known secret. The attacker then submits the forged token to any protected backend API endpoint. The server validates the signature against the same hardcoded secret and grants full administrative access. See GitHub Issue #5 on Vulnerability for further technical context.

Detection Methods for CVE-2026-71801

Indicators of Compromise

• Administrative API requests bearing valid session tokens that do not correspond to any prior successful login event in application logs.
• Session tokens issued to administrative accounts from source IP addresses that have never authenticated interactively.
• Backend API access outside normal business hours or from geographies inconsistent with the administrator's baseline.

Detection Strategies

• Correlate token validation events with authentication events. Flag any accepted token that lacks a preceding successful login for the same subject.
• Inspect the SPMS-Server configuration file for the default access token secret and alert if it matches the shipped value.
• Monitor administrative endpoints for anomalous access patterns, including sudden privilege usage from new sources.

Monitoring Recommendations

• Forward SPMS-Server authentication and API access logs to a centralized analytics platform for correlation and long-term retention.
• Alert on first-seen administrative principals and on token issuance anomalies such as tokens with unusual expiration windows.
• Track configuration file integrity and generate alerts when the token secret value remains at its default.

How to Mitigate CVE-2026-71801

Immediate Actions Required

• Replace the default access token secret in the SPMS-Server configuration file with a cryptographically strong, uniquely generated value per deployment.
• Invalidate all existing session tokens after rotating the secret to force reauthentication of every user and service.
• Restrict network exposure of backend administrative APIs to trusted management networks until the secret has been rotated.

Patch Information

No vendor patch or fixed version is referenced in the available advisory data. Consult the upstream project tracker at GitHub Issue #5 on Vulnerability for updates on a remediated release.

Workarounds

• Override the default token secret through an environment variable or external secret store rather than editing the shipped configuration file.
• Place SPMS-Server behind a reverse proxy that enforces mutual TLS or an additional authentication layer for administrative paths.
• Remove the default secret from any deployed configuration files and rebuild container images without embedded secrets.

# Configuration example: generate and inject a unique token secret
# 1. Generate a strong random secret (32 bytes, base64 encoded)
openssl rand -base64 32

# 2. Export it as an environment variable consumed by SPMS-Server
export SPMS_TOKEN_SECRET="<paste-generated-secret-here>"

# 3. Ensure the production configuration references the env var
#    instead of the hardcoded default, then restart the service.