CVE-2026-86838Network attack vector

Unauthenticated free bookings via unchecked quantity values

Published Sep 28, 2026 · Updated Sep 28, 2026

Payment bypass in Bookly before 28.3 allows remote attackers to book paid appointments for free via manipulated booking quantities. The server computes the appointment total from client-supplied quantity values without validating them, allowing a crafted value to reduce the total to zero and skip payment. Exploitation requires a site offering paid bookings with online payment enabled; Bookly's free plugin does not provide online payments.

CVSS severity5.3
Medium
EPSS probability0.22%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Payment bypass in Bookly before 28.3 allows remote attackers to book paid appointments for free via manipulated booking quantities. The server computes the appointment total from client-supplied quantity values without validating them, allowing a crafted value to reduce the total to zero and skip payment. Exploitation requires a site offering paid bookings with online payment enabled; Bookly's free plugin does not provide online payments.

The record

CVE
CVE-2026-86838
Published
Sep 28, 2026
Updated
Sep 28, 2026
Vendor
Bookly
Product
Bookly
Classifications
CWE-472, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 28, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 28, 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 <28.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Bookly · Booklyversion=0 <28.3

Published CVSS scores

5.3WPScanCVSS:3.1/AV:N/AC:L/PR:N/UI:N/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.

Activity data is delayed. The latest report is Sep 28, 2026.

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

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-472External Control of Assumed-Immutable Web Parameter
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

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Your stack

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