CVE-2026-63228Network attack vector

Server content modification via unrestricted image upload

Published Jul 29, 2026 · Updated Jul 29, 2026

Unrestricted file upload in Three Learning Koollab LMS 5.3.2 allows remote authenticated users to submit malicious content as an image. The feedback mail registration endpoint accepts attacker-supplied content disguised as an image without restricting dangerous file types. Low-privileged access and user interaction are required, and the published impact is limited to modifying server-side content that can support further attacks.

CVSS severity2.6
Low
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Unrestricted file upload in Three Learning Koollab LMS 5.3.2 allows remote authenticated users to submit malicious content as an image. The feedback mail registration endpoint accepts attacker-supplied content disguised as an image without restricting dangerous file types. Low-privileged access and user interaction are required, and the published impact is limited to modifying server-side content that can support further attacks.

The record

CVE
CVE-2026-63228
Published
Jul 29, 2026
Updated
Jul 29, 2026
Vendor
Three Learning
Product
Koollab LMS
Classifications
CWE-434, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 29, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 29, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.3.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Three Learning · Koollab LMSversion=5.3.2

Published CVSS scores

2.6Cyber Security Agency of SingaporeCVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-434Unrestricted Upload of File with Dangerous Type
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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