Summary
CVE-2026-48909 is a critical insecure deserialization vulnerability in SP LMS (com_splms), a Joomla Learning Management System extension developed by JoomShaper. Affecting all versions prior to 4.1.4, the flaw enables an unauthenticated remote attacker to execute arbitrary code on the server by supplying a maliciously crafted serialized PHP object through cookie data. It carries a CVSS 4.0 score of 9.5 (Critical).
Technical details
- Root cause: The extension deserializes user-controlled cookie data without validation (CWE-502: Deserialization of Untrusted Data). Serialized data from browser cookies — specifically in the shopping cart cookie handling logic — is passed directly to PHP’s deserialization routines without sanitization or integrity verification, enabling PHP object injection (CAPEC-586).
- Trigger conditions: No authentication is required. An attacker sends a crafted HTTP request containing a malicious serialized PHP object in the cookie to any Joomla site with the SP LMS extension installed.
- Attack vector: Network-accessible with no user interaction and no prior privileges required. Attack complexity is Low.
- Impact: Successful exploitation results in full remote code execution (RCE) on the underlying server, with high impact on confidentiality, integrity, and availability across both the vulnerable component and connected systems (VC:H/VI:H/VA:H/SC:H/SI:H/SA:H).
Affected software
- SP LMS (com_splms) for Joomla — all versions prior to 4.1.4
Severity
- CVSS 4.0 Base Score: 9.5 (Critical)
- Vector:
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
Mitigation and recommended actions
- Immediate: Upgrade SP LMS to version 4.1.4 or later. JoomShaper released version 4.1.4 on June 17, 2026, directly addressing the object injection vulnerability in cart cookie handling. The update is available from the JoomShaper downloads page.
- If immediate patching is not feasible: Restrict public access to the SP LMS component endpoint (
index.php?option=com_splms) at the web server or firewall level until the update can be applied. This limits the attack surface to the vulnerable deserialization path.
IONIX Status
The IONIX research team is tracking ongoing exploitation attempts and recommends immediate patching. Potentially affected assets are outlined in this post.

