Bookly Plugin up to 28.2 on WordPress external control of assumed-immutable web parameter

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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5.2$0-$5k1.48+

Summaryinfo

A vulnerability classified as problematic has been found in Bookly Plugin up to 28.2. Affected by this issue is some unknown functionality. This manipulation causes external control of assumed-immutable web parameter. This vulnerability appears as CVE-2026-86838. The attack may be initiated remotely. There is no available exploit. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Bookly Plugin up to 28.2. It has been declared as problematic. Affected by this vulnerability is some unknown processing. The manipulation with an unknown input leads to a external control of assumed-immutable web parameter vulnerability. The CWE definition for the vulnerability is CWE-472. The web application does not sufficiently verify inputs that are assumed to be immutable but are actually externally controllable, such as hidden form fields. As an impact it is known to affect integrity. The summary by CVE is:

The Bookly WordPress plugin before 28.3 does not validate client-supplied booking quantity values on the server before computing the appointment total, allowing unauthenticated users to reduce the total to zero and book paid services for free while bypassing the payment step.

It is possible to read the advisory at wpscan.com. This vulnerability is known as CVE-2026-86838 since 09/08/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. The technical details are unknown and an exploit is not publicly available.

Upgrading to version 28.3 eliminates this vulnerability.

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.2

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 5.3
CNA Vector (WPScan): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: External control of assumed-immutable web parameter
CWE: CWE-472
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Bookly Plugin 28.3

Timelineinfo

09/08/2026 CVE reserved
09/28/2026 +20 days Advisory disclosed
09/28/2026 +0 days VulDB entry created
09/28/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: wpscan.com
Status: Confirmed

CVE: CVE-2026-86838 (🔒)
GCVE (CVE): GCVE-0-2026-86838
GCVE (VulDB): GCVE-100-410983

Entryinfo

Created: 09/28/2026 08:58
Changes: 09/28/2026 08:58 (63)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

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