CVE-2026-50769: CRM+ Time-Based SQL Injection Vulnerability

CVE-2026-50769 Overview

CVE-2026-50769 is a time-based SQL injection vulnerability in the Brainformatik CRM+ application affecting all versions up to and including 2025.6. The flaw resides in the calendar conflict-check endpoint index.php?module=Appointments&action=CheckConflictOfDates&ajaxSkipHeader=true, which fails to properly sanitize user-supplied input before incorporating it into SQL queries. An unauthenticated attacker reachable over the network can inject arbitrary SQL statements, exfiltrate database contents, and pivot to arbitrary code execution depending on database privileges. The issue is classified under CWE-89: Improper Neutralization of Special Elements used in an SQL Command.

Critical Impact
Unauthenticated attackers can execute arbitrary SQL against the CRM+ database and potentially achieve remote code execution through the calendar conflict-check endpoint.

Affected Products

Brainformatik CRM+ versions prior to 2025.6
Brainformatik CRM+ version 2025.6
Deployments exposing the Appointments module endpoint

Discovery Timeline

2026-08-17 - CVE-2026-50769 published to NVD
2026-08-18 - Last updated in NVD database

Technical Details for CVE-2026-50769

Vulnerability Analysis

The vulnerability exists in the CheckConflictOfDates action of the Appointments module, which is designed to verify calendar conflicts for users. The endpoint accepts date and identifier parameters that are concatenated directly into a backend SQL query without parameterization or type coercion. Because the endpoint accepts the ajaxSkipHeader=true parameter, authentication and header checks that normally protect other CRM+ actions are bypassed, exposing the query surface to unauthenticated network requests.

Exploitation uses time-based blind techniques. Attackers append conditional SLEEP() or equivalent delay functions to the injected payload and infer data byte-by-byte from server response timing. This allows extraction of database schemas, credential hashes, session tokens, and integration secrets stored within the CRM.

On database engines that permit stacked queries or INTO OUTFILE operations, attackers can escalate from data disclosure to writing files on the underlying host, enabling web shell deployment and arbitrary code execution.

Root Cause

The root cause is direct string concatenation of untrusted HTTP parameters into SQL statements inside the conflict-check handler. Prepared statements and parameter binding are absent, and the ajaxSkipHeader bypass path removes the authentication gate that would otherwise constrain reachability.

Attack Vector

Exploitation requires only network access to the CRM+ web interface. An attacker sends a crafted HTTP request to index.php?module=Appointments&action=CheckConflictOfDates&ajaxSkipHeader=true containing a malicious value in one of the date or record identifier parameters. Time-based payloads confirm injection, after which the attacker automates extraction using tooling such as sqlmap. No user interaction or prior credentials are required.

Technical proof-of-concept material is published in the GitHub CVE-2026-50769 Repository.

Detection Methods for CVE-2026-50769

Indicators of Compromise

HTTP requests to index.php containing module=Appointments, action=CheckConflictOfDates, and ajaxSkipHeader=true from unauthenticated sources.
Query parameter values containing SQL keywords such as SLEEP(, BENCHMARK(, UNION SELECT, INFORMATION_SCHEMA, or encoded variants (0x, CHAR().
Anomalous response latency spikes on the CheckConflictOfDates endpoint indicative of time-based blind extraction.
New files written to CRM+ web directories or unexpected outbound connections from the database service account.

Detection Strategies

Deploy Web Application Firewall (WAF) rules that inspect the Appointments module endpoint for SQL metacharacters and time-delay functions.
Correlate database audit logs for queries containing SLEEP or BENCHMARK originating from the CRM+ application user.
Monitor endpoint telemetry on CRM+ web servers for child processes spawned by the PHP interpreter, such as shells or scripting engines.

Monitoring Recommendations

Enable verbose access logging on the CRM+ web tier and forward logs to a centralized analytics platform.
Baseline normal request-duration distributions for CheckConflictOfDates and alert on statistical outliers.
Track database privilege usage to detect abuse of file-write functions such as INTO OUTFILE or LOAD_FILE.

How to Mitigate CVE-2026-50769

Immediate Actions Required

Restrict network access to the CRM+ application to trusted networks or VPN users until a vendor patch is applied.
Block or rate-limit requests to the Appointments&action=CheckConflictOfDates endpoint at the reverse proxy or WAF.
Audit the CRM+ database for unexpected accounts, exported tables, or file-write activity that may indicate prior exploitation.
Rotate credentials, API tokens, and integration secrets stored inside CRM+ once containment is verified.

Patch Information

Brainformatik has not published a fixed release identifier in the referenced advisory materials at the time of writing. Administrators should consult the Brainformatik Website for updates beyond version 2025.6 and apply them as soon as they are available.

Workarounds

Add a WAF rule denying any request whose query string contains both action=CheckConflictOfDates and SQL metacharacters such as single quotes, semicolons, or the strings SLEEP and BENCHMARK.
Require authenticated sessions for the Appointments module by removing or ignoring the ajaxSkipHeader=true bypass at the front-end proxy.
Restrict the database account used by CRM+ to least privilege, removing FILE, CREATE, and SUPER permissions to limit post-exploitation options.

bash

# Example NGINX rule to block exploitation attempts against the vulnerable endpoint
location ~* /index\.php {
    if ($arg_action = "CheckConflictOfDates") {
        set $block_sqli 1;
    }
    if ($args ~* "(sleep\(|benchmark\(|union.*select|information_schema|into\s+outfile)") {
        set $block_sqli "${block_sqli}1";
    }
    if ($block_sqli = "11") {
        return 403;
    }
}