CVE-2026-71276: Magistrala SQL Injection Vulnerability

CVE-2026-71276 Overview

CVE-2026-71276 is a SQL injection vulnerability in Magistrala (formerly Mainflux), an open-source IoT messaging platform. The message-readers API reads a format value from the HTTP query string without validation and interpolates it directly into raw SQL queries using fmt.Sprintf(). Both the PostgreSQL and TimescaleDB readers share this unsafe pattern. Any authenticated user able to query channel messages can inject arbitrary SQL statements. The flaw is tracked under CWE-89: SQL Injection.

Critical Impact
Authenticated attackers can execute arbitrary SQL against the messages database, exposing tenant channel data and potentially other schema contents.

Affected Products

Magistrala (formerly Mainflux) IoT platform
Magistrala PostgreSQL message reader (readers/postgres/messages.go)
Magistrala TimescaleDB message reader (readers/timescale/messages.go)

Discovery Timeline

2026-08-05 - CVE-2026-71276 published to NVD
2026-08-05 - Last updated in NVD database

Technical Details for CVE-2026-71276

Vulnerability Analysis

The vulnerability resides in Magistrala's HTTP transport layer for message reads. The handler in readers/api/http/transport.go accepts a format query parameter from the client and forwards it to the storage backend without sanitization or allow-listing. Both backend implementations then compose SQL statements through string formatting rather than parameterized queries.

In the PostgreSQL reader, the query is built as fmt.Sprintf("SELECT * FROM %s WHERE %s ...", format, cond). The TimescaleDB reader follows the same pattern. Because format is used as the table identifier in a raw statement, attackers can append UNION selects, subqueries, or stacked statements to exfiltrate data from other tables or manipulate query logic.

Exploitation requires authentication and permission to query channel messages, which limits pre-auth exposure. However, in multi-tenant Magistrala deployments any tenant user can reach the vulnerable endpoint, making cross-tenant data disclosure the primary concern.

Root Cause

The root cause is improper neutralization of special elements used in an SQL command [CWE-89]. Table identifiers cannot be bound as parameters in standard SQL drivers, so developers used fmt.Sprintf() interpolation. The format value must instead be validated against a strict allow-list of known table names before use.

Attack Vector

An authenticated user sends a crafted HTTP request to the message-readers API and supplies a malicious format query parameter. The value is concatenated directly into the SQL statement executed against PostgreSQL or TimescaleDB. Attackers use standard SQL injection techniques such as UNION-based extraction, boolean-based blind inference, or time-delay probing to read arbitrary data.

See the Magistrala repository and the vulnerable PostgreSQL reader source for the affected code paths.

Detection Methods for CVE-2026-71276

Indicators of Compromise

HTTP requests to /readers, /channels/{id}/messages, or related message endpoints containing SQL metacharacters in the format parameter (single quotes, --, UNION, SELECT, ;).
Unusually long or URL-encoded format values in Magistrala HTTP access logs.
PostgreSQL or TimescaleDB error entries referencing malformed identifiers originating from Magistrala's reader service.
Unexpected SELECT activity against system catalogs (pg_catalog, information_schema) from the Magistrala database role.

Detection Strategies

Inspect application and reverse-proxy logs for the format= query parameter and alert on non-alphanumeric values.
Deploy web application firewall rules that reject SQL keywords in the format parameter for Magistrala endpoints.
Enable PostgreSQL statement logging (log_statement = 'all') on the messages database and correlate anomalous SELECT patterns with Magistrala API calls.

Monitoring Recommendations

Baseline normal format values (json, senml) and alert on any deviation.
Monitor database role activity for queries touching tables outside the expected message schemas.
Track authentication events for accounts issuing high volumes of reader API calls in short windows.

How to Mitigate CVE-2026-71276

Immediate Actions Required

Restrict access to the Magistrala message-readers API to trusted users until a patched release is deployed.
Place a reverse proxy or WAF in front of Magistrala to reject non-allow-listed values of the format query parameter.
Rotate any database credentials that may have been exposed through query logs.
Audit PostgreSQL and TimescaleDB logs for suspicious statements originating from the reader service.

Patch Information

No fixed version was listed in the NVD entry at publication. Track the Magistrala GitHub repository for a release that validates the format parameter against an allow-list and replaces fmt.Sprintf() interpolation with safe identifier handling.

Workarounds

Apply a local patch that validates format against a hardcoded set ({"json", "senml"}) before it reaches the SQL layer.
Enforce least privilege on the database role used by the reader service, restricting SELECT to the messages schema only.
Disable or firewall the reader API in deployments that do not require historical message queries.

bash

# Example nginx rule to allow only known-safe format values
location /readers {
    if ($arg_format !~ ^(json|senml)$) {
        return 400;
    }
    proxy_pass http://magistrala_readers;
}