CVE-2026-13569: SQL Injection in EyouCMS API click_like Parameter

Technical summary

The vulnerability is a SQL injection flaw (CWE-89) in EyouCMS's API layer. The /index.php endpoint fails to properly sanitize the 'click_like' parameter before incorporating it into SQL queries. An attacker with elevated privileges (PR:H) can craft malicious input to break out of the intended query context and execute arbitrary SQL. The attack vector is network-based with low complexity, meaning it requires no special network positioning or timing. The vulnerability also exhibits improper neutralization of special elements used in SQL (CWE-74), suggesting inadequate input validation and parameterization practices.

Business impact

Organizations running EyouCMS as a content management system face potential data exfiltration, unauthorized modification of website content, and database corruption. If the CMS instance hosts customer data, order information, or user credentials, a compromise could lead to data breach notifications, regulatory fines, and reputational damage. The requirement for authenticated access reduces immediate risk for internet-facing instances without valid user accounts, but internal threats or credential compromise significantly increase exposure. Business continuity may be affected if database integrity is compromised.

Affected systems

EyouCMS versions up to and including 1.7.1 are confirmed vulnerable. The affected component is the API handler in /index.php. Organizations using this CMS should audit their deployment versions and access logs to determine exposure. Verify exact version numbers in your instances, as the source data does not specify when the vulnerability was introduced.

Exploitability

While a CVSS score of 4.7 (MEDIUM) reflects the requirement for authenticated access, the public availability of exploit code and working proof-of-concept materials significantly increases practical risk. An attacker who obtains valid EyouCMS administrative credentials—through phishing, password reuse, or compromised accounts—can immediately leverage this flaw without sophisticated technical skill. The low attack complexity means straightforward HTTP requests with malicious payloads are sufficient.

Remediation

Update EyouCMS to a patched version released by weng-xianhu after June 2026. Verify patch availability through the official EyouCMS project channels, as the vendor has not yet publicly acknowledged this report. Until a patch is available, implement the mitigations below. Organizations should also audit administrative account access, enforce strong password policies, and monitor API endpoints for suspicious database query patterns.

Patch guidance

Contact weng-xianhu or monitor their official repository and security advisories for a patched release addressing CVE-2026-13569. Given the vendor's silence as of the report date, prepare for a potentially delayed patch cycle. In parallel, implement temporary compensating controls: restrict administrative access to trusted networks only, enable detailed API request logging, and monitor database query performance metrics for anomalies. Document your current EyouCMS version number and plan a maintenance window for patching as soon as a release becomes available.

Detection guidance

Monitor /index.php API requests for suspicious 'click_like' parameter values, particularly those containing SQL syntax characters (single quotes, semicolons, UNION keywords, SELECT, DROP, etc.). Enable query logging on the backend database and search for unexpected SQL patterns or errors. Look for HTTP POST/GET requests to /index.php from authenticated administrative accounts with unusual payload sizes or encoding. Implement Web Application Firewall (WAF) rules to block known SQL injection signatures targeting the click_like parameter. Review access logs for accounts accessing the vulnerable endpoint outside normal business hours.

Why prioritize this

Prioritize patching after medium-to-high risk items but within 30 days. The MEDIUM CVSS score reflects the authenticated access requirement, which provides a natural barrier against unauthenticated attacks. However, the public availability of exploit code and the vendor's lack of response create urgency. Any organization with weak administrative credential hygiene or exposed EyouCMS instances on the internet should elevate this to high priority. The SQL injection nature means database compromise is possible if credentials are breached.

Risk score, explained

The CVSS 3.1 score of 4.7 reflects: (1) Network-based attack vector with no authentication bypass, (2) High privilege requirement (PR:H), (3) Low attack complexity, and (4) Limited impact scope—the attacker gains low confidentiality, integrity, and availability impact within the scope of the database. The score does not account for the public exploit availability, which raises practical risk beyond the numerical score. Organizations should factor in their own administrative access controls and database criticality when making remediation decisions.

Frequently asked questions