CVE-2026-81342Network attack vectorHinoki check available

Unauthenticated external redirect via unvalidated registration parameter

Published Aug 29, 2026 · Updated Aug 29, 2026

Open redirect in MasterStudy LMS before 3.7.43 allows remote attackers to send registering users to arbitrary external URLs. The registration handler uses an attacker-supplied redirect parameter without validating that its destination remains on the site. Exploitation requires a user to follow the crafted registration flow, exposing that user to an attacker-chosen external site.

CVSS severity4.7
Medium
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Open redirect in MasterStudy LMS before 3.7.43 allows remote attackers to send registering users to arbitrary external URLs. The registration handler uses an attacker-supplied redirect parameter without validating that its destination remains on the site. Exploitation requires a user to follow the crafted registration flow, exposing that user to an attacker-chosen external site.

The record

CVE
CVE-2026-81342
Published
Aug 29, 2026
Updated
Aug 29, 2026
Vendor
StylemixThemes
Product
MasterStudy LMS
Classifications
CWE-601, CAPEC-178, T1204.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 29, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 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=0 <3.7.43

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

StylemixThemes · MasterStudy LMSversion=0 <3.7.43

Published CVSS scores

4.7GitHub Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-601URL Redirection to Untrusted Site ('Open Redirect')
CAPEC-178Cross-Site Flashing
T1204.001User Execution: Malicious Link

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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