CVE-2026-82845Network attack vectorHinoki check available

Server code execution via stored metadata deserialization

Published Sep 12, 2026 · Updated Sep 12, 2026

PHP object injection in ThemeGrill Masteriyo LMS before 3.4.1 allows remote authenticated users to execute server code via stored metadata. Metadata readback passes attacker-controlled stored values to PHP deserialization without preventing object instantiation. Subscriber-level access enables code execution through a bundled-library gadget chain; a separate unauthenticated path is limited to arbitrary file writes.

CVSS severityUnavailable
Unscored
EPSS probability0.35%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

PHP object injection in ThemeGrill Masteriyo LMS before 3.4.1 allows remote authenticated users to execute server code via stored metadata. Metadata readback passes attacker-controlled stored values to PHP deserialization without preventing object instantiation. Subscriber-level access enables code execution through a bundled-library gadget chain; a separate unauthenticated path is limited to arbitrary file writes.

The record

CVE
CVE-2026-82845
Published
Sep 12, 2026
Updated
Sep 12, 2026
Vendor
ThemeGrill
Product
Masteriyo LMS
Classifications
T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 12, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 12, 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 <3.4.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

ThemeGrill · Masteriyo LMSversion=0 <3.4.1

Published CVSS scores

No CVSS assessment is available in this record.

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

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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