CVE-2026-40815: _mb24api_getUserAccount SQL Injection Flaw

CVE-2026-40815 Overview

CVE-2026-40815 is an unauthenticated SQL injection vulnerability in the _mb24api_getUserAccount function. The flaw stems from improper neutralization of special elements used in a SQL SELECT statement [CWE-89]. A remote attacker can send crafted input over the network without authentication or user interaction. Successful exploitation results in a total loss of confidentiality of data accessible to the backend database. CERT-VDE published a security advisory tracking this issue under VDE-2026-044.

Critical Impact
Unauthenticated attackers can extract sensitive database contents remotely by injecting SQL into the _mb24api_getUserAccount API endpoint.

Affected Products

The affected product list was not enumerated in the NVD record at publication time. Refer to the CERT-VDE Security Advisory VDE-2026-044 for the authoritative inventory of vulnerable products and versions.

Discovery Timeline

2026-05-27 - CVE-2026-40815 published to the National Vulnerability Database (NVD)
2026-05-27 - Last updated in NVD database

Technical Details for CVE-2026-40815

Vulnerability Analysis

The vulnerability resides in the _mb24api_getUserAccount function. This function accepts attacker-controlled input and concatenates it into a SQL SELECT statement without proper sanitization or parameterization. Because the endpoint does not require authentication, any remote client reachable over the network can issue malicious queries. The flaw maps to [CWE-89] (Improper Neutralization of Special Elements used in an SQL Command). The EPSS probability sits at 0.049% (15.5 percentile), indicating that public exploitation activity has not yet been observed.

Root Cause

The root cause is the construction of SQL statements through direct string concatenation of untrusted input. Input passed to _mb24api_getUserAccount reaches the database query layer without prepared statements or input validation. Special SQL syntax characters such as single quotes, semicolons, and comment sequences alter the structure of the original query. The function additionally lacks authentication checks, exposing the injection point to anonymous network attackers.

Attack Vector

The attack vector is network-based and requires no authentication or user interaction. An attacker crafts an HTTP request to the API route invoking _mb24api_getUserAccount and supplies SQL metacharacters within the user account parameter. The injected payload modifies the SELECT query to return arbitrary rows, including data from other tables via UNION-based techniques. Confidentiality impact is rated High, while integrity and availability are unaffected per the CVSS vector.

No verified proof-of-concept code is available. Detailed exploit mechanics are described in the CERT-VDE Security Advisory.

Detection Methods for CVE-2026-40815

Indicators of Compromise

HTTP requests to API paths containing _mb24api_getUserAccount with SQL metacharacters such as ', --, ;, UNION, or SELECT in query parameters.
Anomalous database query patterns originating from the web application service account, including queries against system or user tables outside normal application logic.
Unexpected response sizes or error messages from the _mb24api_getUserAccount endpoint indicating query structure changes.

Detection Strategies

Deploy web application firewall (WAF) signatures that inspect requests to the _mb24api_getUserAccount endpoint for SQL injection patterns.
Enable database query logging and alert on queries containing UNION SELECT, information_schema, or tautologies such as OR 1=1 originating from the application tier.
Correlate authentication logs with API access logs to surface unauthenticated access attempts against account-related endpoints.

Monitoring Recommendations

Capture full HTTP request bodies and query strings for the affected API for retrospective analysis.
Monitor outbound data volumes from the database server to detect bulk extraction attempts.
Track HTTP 500 and SQL error responses returned to clients, as injection attempts often generate parser errors.

How to Mitigate CVE-2026-40815

Immediate Actions Required

Restrict network exposure of the affected API endpoint using firewall rules or reverse proxy ACLs until a patch is applied.
Review database and web server logs for prior exploitation attempts referencing _mb24api_getUserAccount.
Apply the vendor patch identified in CERT-VDE advisory VDE-2026-044 as soon as it becomes available for your product version.
Rotate credentials and secrets that may have been exposed through the vulnerable database account.

Patch Information

Refer to the CERT-VDE Security Advisory VDE-2026-044 for vendor-specific patch availability and remediation guidance. The NVD entry does not list fixed versions at the time of publication.

Workarounds

Place the affected service behind an authenticating reverse proxy to block unauthenticated requests to _mb24api_getUserAccount.
Deploy WAF rules that reject requests containing SQL metacharacters in parameters consumed by the vulnerable function.
Apply least-privilege permissions to the database account used by the application to limit the scope of data accessible through injection.

bash

# Example WAF rule (ModSecurity) blocking SQLi patterns on the affected endpoint
SecRule REQUEST_URI "@contains _mb24api_getUserAccount" \
    "id:1040815,phase:2,deny,status:403,\
     chain,msg:'CVE-2026-40815 SQLi attempt'"
    SecRule ARGS "@rx (?i)(\bunion\b.*\bselect\b|--|;|\bor\b\s+1=1)" \
        "t:none,t:urlDecodeUni"