CVE-2026-9851Network attack vector

Editor-to-Administrator escalation via unchecked account update

Published Jun 6, 2026 · Updated Jun 6, 2026

Privilege escalation in MASAAKI TANAKA Booking Package 1.7.16 and earlier allows remote authenticated users to take over administrator accounts. The package_app_action AJAX handler validates only a nonce, then passes attacker-selected user data to Schedule::updateUser() with its administrator flag forced to 1, bypassing the owner check before wp_update_user(). Editor-level access is required; changing an administrator email address and password grants control of that account and the WordPress site.

CVSS severity7.2
High
EPSS probability0.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Privilege escalation in MASAAKI TANAKA Booking Package 1.7.16 and earlier allows remote authenticated users to take over administrator accounts. The package_app_action AJAX handler validates only a nonce, then passes attacker-selected user data to Schedule::updateUser() with its administrator flag forced to 1, bypassing the owner check before wp_update_user(). Editor-level access is required; changing an administrator email address and password grants control of that account and the WordPress site.

The record

CVE
CVE-2026-9851
Published
Jun 6, 2026
Updated
Jun 6, 2026
Vendor
MASAAKI TANAKA
Product
Booking Package
Classifications
CWE-639, T1098
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 6, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=0 <=1.7.16

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

MASAAKI TANAKA · Booking Packageversion=0 <=1.7.16

Published CVSS scores

7.2WordfenceCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-639Authorization Bypass Through User-Controlled Key
T1098Account Manipulation

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo