Three Learning Koollab LMS 5.3.2 Feedback Mail Registration Endpoint unrestricted upload

Summaryinfo

A vulnerability was found in Three Learning Koollab LMS 5.3.2. It has been classified as critical. This affects an unknown part of the component Feedback Mail Registration Endpoint. This manipulation causes unrestricted upload. This vulnerability is tracked as CVE-2026-63228. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability classified as critical was found in Three Learning Koollab LMS 5.3.2. Affected by this vulnerability is an unknown code block of the component Feedback Mail Registration Endpoint. The manipulation with an unknown input leads to a unrestricted upload vulnerability. The CWE definition for the vulnerability is CWE-434. The product allows the attacker to upload or transfer files of dangerous types that can be automatically processed within the product's environment. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

An unrestricted image upload vulnerability in Koollab LMS allowed an authenticated attacker to upload malicious content disguised as an image file via the feedback mail registration endpoint, potentially enabling further attacks on the server.

It is possible to read the advisory at csa.gov.sg. This vulnerability is known as CVE-2026-63228 since 07/16/2026. The exploitation appears to be easy. The attack can be launched remotely. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 07/29/2026). The attack technique deployed by this issue is T1608.002 according to MITRE ATT&CK.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Vendor

• Three Learning

Name

• Koollab LMS

Version

• 5.3.2

CPE 2.3info

• 🔒

CPE 2.2info

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