Online Scheduling and Appointment Booking System Plugin deserialization

CVSS Meta Temp Score
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CTI Interest Score
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6.0$0-$5k0.49

Summaryinfo

A vulnerability classified as critical was found in Online Scheduling and Appointment Booking System Plugin up to 28.2. Affected is an unknown function. Such manipulation leads to deserialization. This vulnerability is documented as CVE-2026-86841. The attack can be executed remotely. There is not any exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Online Scheduling and Appointment Booking System Plugin up to 28.2. Affected by this issue is an unknown function. The manipulation with an unknown input leads to a deserialization vulnerability. Using CWE to declare the problem leads to CWE-502. The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid. Impacted is confidentiality, integrity, and availability. CVE summarizes:

The Online Scheduling and Appointment Booking System WordPress plugin before 28.3 does not prevent deserialization of untrusted input and does not correctly restrict a privileged maintenance feature to administrators, allowing users granted a custom booking-management capability, which an administrator must explicitly assign, to inject arbitrary PHP objects, overwrite privileged site options, and read stored integration secrets.

The advisory is shared for download at wpscan.com. This vulnerability is handled as CVE-2026-86841 since 09/08/2026. The exploitation is known to be easy. The attack may be launched remotely. There are neither technical details nor an exploit publicly available.

Upgrading to version 28.3 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-87891). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.3
VulDB Meta Temp Score: 6.0

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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

Exploitinginfo

Class: Deserialization
CWE: CWE-502 / CWE-20
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

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: Online Scheduling and Appointment Booking System Plugin 28.3

Timelineinfo

09/08/2026 CVE reserved
09/27/2026 +19 days Advisory disclosed
09/27/2026 +0 days VulDB entry created
09/28/2026 +1 days VulDB entry last update

Sourcesinfo

Advisory: wpscan.com
Status: Confirmed

CVE: CVE-2026-86841 (🔒)
GCVE (CVE): GCVE-0-2026-86841
GCVE (VulDB): GCVE-100-410816
EUVD: 🔒

Entryinfo

Created: 09/27/2026 08:10
Updated: 09/28/2026 06:50
Changes: 09/27/2026 08:10 (54), 09/28/2026 06:50 (1)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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