CVE-2026-57310: Windu CMS Information Disclosure Flaw

CVE-2026-57310 Overview

CVE-2026-57310 affects Windu CMS, which stores user passwords using a hashing scheme based on MD5 and SHA1 combined with a static salt. An attacker who obtains the password hashes can recover the underlying credentials through brute-force or precomputed dictionary attacks. The weakness is classified under [CWE-916]: Use of Password Hash With Insufficient Computational Effort.

The issue has been confirmed in Windu CMS version 4.1. Vendor contact attempts were unsuccessful, so other versions may also be affected. Public technical details are available in the CERT Polska Security Analysis.

Critical Impact
An attacker who obtains stored password hashes can recover plaintext credentials because the algorithm relies on fast, unsalted-per-user primitives.

Affected Products

Windu CMS 4.1 (confirmed)
Earlier Windu CMS versions (potentially affected, unverified)
Deployments relying on the built-in Windu authentication database

Discovery Timeline

2026-07-20 - CVE-2026-57310 published to NVD
2026-07-22 - Last updated in NVD database

Technical Details for CVE-2026-57310

Vulnerability Analysis

Windu CMS derives password digests by chaining MD5 and SHA1, both of which are fast, general-purpose cryptographic hashes. Neither algorithm is designed for password storage. Modern GPUs compute billions of MD5 and SHA1 operations per second, which makes offline recovery of credentials practical once the hash database leaks.

The implementation also applies a single static salt shared across all user accounts. A static salt fails to defeat precomputed rainbow tables and does not increase the cost per guess. Attackers can build one table for the deployment and reuse it against every user record.

Credential compromise leads to account takeover of CMS users, including administrative accounts if their hashes are exposed. Downstream impact includes unauthorized content modification, malicious script injection into published pages, and lateral access if users reuse passwords across systems.

Root Cause

The root cause is the selection of unsuitable password storage primitives. Secure password storage requires adaptive functions such as bcrypt, scrypt, Argon2, or PBKDF2 with a per-user random salt and a tunable work factor. Windu CMS instead uses fast hashes with a fixed salt hardcoded in the application, eliminating both per-user uniqueness and computational cost as defenses.

Attack Vector

Exploitation requires prior access to the stored password hashes. Typical acquisition paths include SQL injection against the CMS database, backup file exposure, misconfigured storage buckets, or insider access. Once the hash and static salt are known, the attacker performs offline cracking without further interaction with the target server.

The vulnerability is described in prose because no verified proof-of-concept code is published. Refer to the CERT Polska Security Analysis for further technical background.

Detection Methods for CVE-2026-57310

Indicators of Compromise

Unexpected successful logins to Windu CMS administrative accounts from unfamiliar IP addresses or geolocations.
Database read queries targeting the users table, especially SELECT statements returning password hash columns.
Backup files or database dumps of Windu CMS present on public-facing storage or web-accessible paths.
New administrator accounts, modified user roles, or altered published content without a corresponding change request.

Detection Strategies

Monitor authentication logs for password-spraying and credential-stuffing patterns against Windu CMS login endpoints.
Alert on bulk read access to the CMS user table from application service accounts outside normal query patterns.
Inspect outbound traffic for exfiltration of database dumps or archive files originating from the CMS host.
Correlate CMS login events with threat intelligence on credentials leaked from third-party breaches.

Monitoring Recommendations

Enable verbose authentication logging in Windu CMS and ship logs to a centralized SIEM for retention and correlation.
Track failed login attempts per account and per source IP, and alert on thresholds indicative of brute-force behavior.
Audit database access to the users table on a scheduled cadence and review any query that returns hash material.
Baseline administrator activity and alert on privilege changes, plugin installation, or template modification outside change windows.

How to Mitigate CVE-2026-57310

Immediate Actions Required

Restrict network exposure of the Windu CMS administrative interface to trusted IP ranges or a VPN.
Force a password reset for all Windu CMS users and require passwords that resist offline cracking.
Rotate any credentials that may have been reused across Windu CMS and other systems.
Audit database backups and remove copies of the users table from any publicly accessible location.

Patch Information

No vendor patch is available. CERT Polska reports that vendor contact attempts were unsuccessful. Organizations running Windu CMS should evaluate migration to an actively maintained CMS or apply the workarounds below until a fix is released. Monitor the Windu project site for updates.

Workarounds

Place Windu CMS behind a Web Application Firewall (WAF) and block direct database access from the internet.
Enforce multi-factor authentication at a reverse proxy or identity provider in front of the CMS login page.
Replace the password storage routine with bcrypt or Argon2id and a per-user random salt if source-level modifications are feasible.
Isolate the CMS database on a segmented network and restrict read permissions on the users table to the minimum required service account.

bash

# Example: enforce HTTPS and IP allow-listing for the admin path in nginx
location /admin/ {
    allow 10.0.0.0/24;
    deny all;
    proxy_pass http://windu_backend;
    proxy_set_header X-Forwarded-Proto https;
}