CVE-2026-40546: SOPlanning SQL Injection Vulnerability

CVE-2026-40546 Overview

CVE-2026-40546 is a SQL Injection vulnerability affecting SOPlanning version 1.55 and below. SOPlanning is an open-source online project planning tool used to manage tasks, resources, and schedules. The flaw spans multiple endpoints and parameters across the application. An authenticated attacker with low privileges can inject arbitrary SQL statements into vulnerable queries. Successful exploitation allows attackers to read, modify, or delete database contents and potentially gain full control over the backend database.

Critical Impact

Low-privileged authenticated attackers can execute arbitrary SQL commands against the SOPlanning database, leading to full disclosure or compromise of stored planning, user, and credential data.

Affected Products

• SOPlanning version 1.55
• SOPlanning versions below 1.55
• Self-hosted SOPlanning deployments exposing the web interface

Discovery Timeline

• 2026-06-01 - CVE-2026-40546 published to NVD
• 2026-06-01 - Last updated in NVD database

Technical Details for CVE-2026-40546

Vulnerability Analysis

The vulnerability is classified as SQL Injection [CWE-89]. SOPlanning fails to properly sanitize or parameterize user-supplied input before incorporating it into SQL queries. The defect is not isolated to one feature. Multiple endpoints and request parameters across the application accept attacker-controlled values that flow directly into database queries.

Because authentication is required, exploitation depends on attacker possession of any valid low-privilege account. Many SOPlanning installations provision shared planner accounts, which lowers the practical barrier. Once authenticated, an attacker can manipulate query logic to extract arbitrary tables, including user credentials, project data, and session records.

The attack is network-reachable and requires no user interaction. Impact on confidentiality and integrity is high, while availability impact is lower because the primary risk is data exposure and tampering rather than service disruption.

Root Cause

The root cause is improper neutralization of special elements used in SQL commands. Affected code paths concatenate request parameters into SQL strings instead of using prepared statements or parameterized queries. The pattern repeats across several PHP endpoints, indicating a systemic input handling weakness rather than a single isolated bug.

Attack Vector

The attack vector is network-based over HTTP or HTTPS against the SOPlanning web interface. An attacker authenticates with any low-privileged account, then submits crafted query string or POST body parameters to vulnerable endpoints. The injected payload alters query semantics, enabling boolean-based, error-based, or UNION-based extraction techniques. See the CERT Polska advisory for technical context on the affected endpoints.

Detection Methods for CVE-2026-40546

Indicators of Compromise

• HTTP requests to SOPlanning endpoints containing SQL metacharacters such as ', --, UNION SELECT, OR 1=1, or SLEEP( in parameter values.
• Web server access logs showing repeated authenticated requests from a single session to varied SOPlanning endpoints within short time windows.
• Database error messages returned in HTTP responses or recorded in application logs referencing MySQL or MariaDB syntax errors.
• Unexpected reads against the users or utilisateur tables originating from the SOPlanning application account.

Detection Strategies

• Deploy web application firewall rules that flag SQL injection signatures targeting SOPlanning endpoint paths.
• Enable MySQL or MariaDB general query logging on the SOPlanning database and alert on queries containing UNION, INFORMATION_SCHEMA references, or stacked statements from the application user.
• Correlate authenticated SOPlanning sessions with abnormal query volumes or query patterns deviating from baseline planner activity.

Monitoring Recommendations

• Monitor outbound data volume from the SOPlanning host for signs of bulk database exfiltration.
• Track failed login attempts and newly created low-privilege accounts that could be used to reach the authenticated attack surface.
• Review web server logs for parameter fuzzing patterns and automated scanner user agents such as sqlmap.

How to Mitigate CVE-2026-40546

Immediate Actions Required

• Upgrade SOPlanning to a version above 1.55 once the maintainers publish a fixed release.
• Restrict access to the SOPlanning web interface to trusted networks or VPN users until patching is complete.
• Audit existing SOPlanning user accounts and disable unused or shared low-privilege accounts that could serve as an entry point.
• Rotate database credentials and session secrets if any indicator of exploitation is found.

Patch Information

No vendor patch reference is included in the current advisory data. Administrators should monitor the SOPlanning project site and the CERT Polska advisory for fix availability and apply the update as soon as it is released.

Workarounds

• Place SOPlanning behind a web application firewall with SQL injection signatures enabled and tuned for PHP applications.
• Constrain the database account used by SOPlanning to the minimum required privileges, removing FILE, CREATE, and cross-database access.
• Enforce strong authentication and limit account provisioning to reduce the pool of low-privileged users who could exploit the flaw.
• Enable verbose database query logging to support rapid forensic review if exploitation is suspected.

# Example: restrict SOPlanning DB user to least privilege in MySQL
REVOKE ALL PRIVILEGES ON *.* FROM 'soplanning'@'localhost';
GRANT SELECT, INSERT, UPDATE, DELETE ON soplanning_db.* TO 'soplanning'@'localhost';
FLUSH PRIVILEGES;