ladela Bookly Plugin up to 27.0 on WordPress Negative Number tips external control of assumed-immutable web parameter

Summaryinfo

A vulnerability has been found in ladela Bookly Plugin up to 27.0 on WordPress and classified as critical. Affected by this issue is some unknown functionality of the component Negative Number Handler. The manipulation of the argument tips leads to external control of assumed-immutable web parameter. This vulnerability is referenced as CVE-2026-2519. Remote exploitation of the attack is possible. No exploit is available.

Detailsinfo

A vulnerability, which was classified as critical, has been found in ladela Bookly Plugin up to 27.0 on WordPress. This issue affects an unknown part of the component Negative Number Handler. The manipulation of the argument tips with an unknown input leads to a external control of assumed-immutable web parameter vulnerability. Using CWE to declare the problem leads to 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. Impacted is integrity, and availability. The summary by CVE is:

The Online Scheduling and Appointment Booking System – Bookly plugin for WordPress is vulnerable to price manipulation via the 'tips' parameter in all versions up to, and including, 27.0. This is due to the plugin trusting a user-supplied input without server-side validation against the configured price. This makes it possible for unauthenticated attackers to submit a negative number to the 'tips' parameter, causing the total price to be reduced to zero.

The weakness was published by Youssef Elouaer. It is possible to read the advisory at wordfence.com. The identification of this vulnerability is CVE-2026-2519 since 02/15/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 04/09/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-20890). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

• WordPress Plugin

Vendor

• ladela

Name

• Bookly Plugin

Version

• 27.0

CPE 2.3info

• 🔒

CPE 2.2info

• 🔒

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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