CVE-2026-92561

Booking Calendar <= 11.8.2 - Reflected Cross-Site Scripting via 'options' Parameter

2026-09-17 18:25

Strategic Overview

Status: Patched in 11.8.3
Affected Plugin: Booking Calendar
Affected Version: <= 11.8.2
CVSS: 6.1Medium
Weakness type: CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE: CVE-2026-92561

View all Booking Calendar vulnerabilities

At a glance

CVE-2026-92561 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Booking Calendar WordPress plugin, affecting versions <= 11.8.2. It carries a CVSS score of 6.1 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 11.8.3; sites on affected versions should update now. Disclosed September 2026, reported by Yuto Hyakumoto.

Vulnerability Overview

The Booking Calendar plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the 'options' parameter in all versions up to, and including, 11.8.2 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link. The nonce check is bypassed by default because the 'booking_is_nonce_at_front_end' option ships disabled, allowing unauthenticated requests to reach the vulnerable sink without any verification.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site.

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Booking Calendar <= 11.8.2 carries this weakness at options, and reaching it takes a caller who can reach the endpoint. Cross-site scripting happens when input from a request is written into a page without being escaped for the context it lands in, so the browser parses attacker-supplied text as markup or script.

Injected script runs with the privileges of whoever views the affected page, which is how these flaws turn into administrator session theft, silent account creation or persistent backdoors in page content. For Booking Calendar the fix is 11.8.3: builds <= 11.8.2 are affected, anything from 11.8.3 onward is not.

Remediation

Update to version 11.8.3, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Booking Calendar: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Booking Calendar 11.8.3 closes this, and updating the plugin is the step that ends it.

Firewall
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-92561 https://www.wordfence.com/threat-intel/vulnerabilities/id/e8645b58-6b2a-4659-a002-d622453bea42 https://nvd.nist.gov/vuln/detail/CVE-2026-92561

Related records

Same weakness class

Other vulnerabilities in Booking Calendar

CVSS Vector

6.1

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionRequired
ScopeChanged
ConfidentialityLow
IntegrityLow
AvailabilityNone

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