CVE-2026-16540Public exploitNetwork attack vector

Unauthenticated appointment disclosure and deletion via purge

Published Aug 2, 2026 · Updated Aug 2, 2026

Incorrect authorization in Simply Schedule Appointments before 1.6.12.6 allows remote attackers to disclose all appointment data. The purge REST endpoint accepts one self-booked appointment ID and public token, then creates a site-wide backup CSV before applying bulk filters beyond that appointment. A public booking form is required; free editions expose the CSV, while premium editions also permanently delete matching appointments.

CVSS severity7.5
High
EPSS probability0.42%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect authorization in Simply Schedule Appointments before 1.6.12.6 allows remote attackers to disclose all appointment data. The purge REST endpoint accepts one self-booked appointment ID and public token, then creates a site-wide backup CSV before applying bulk filters beyond that appointment. A public booking form is required; free editions expose the CSV, while premium editions also permanently delete matching appointments.

The record

CVE
CVE-2026-16540
Published
Aug 2, 2026
Updated
Aug 2, 2026
Vendor
N Squared Digital, LLC
Product
Simply Schedule Appointments
Classifications
CWE-863, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 2, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 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 <1.6.12.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

N Squared Digital, LLC · Simply Schedule Appointmentsversion=0 <1.6.12.6

Published CVSS scores

7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/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 exploitPublished

Weakness, pattern, technique

CWE-863Incorrect Authorization
T1190Exploit Public-Facing Application

Public exploit references

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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