croixhaug Simply Schedule Appointments Plugin up to 1.6.12.27 on WordPress ssa_locale file inclusion

Summaryinfo

A vulnerability identified as critical has been detected in croixhaug Simply Schedule Appointments Plugin up to 1.6.12.27. This affects an unknown function. Performing a manipulation of the argument ssa_locale results in file inclusion. This vulnerability was named CVE-2026-89294. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability classified as critical has been found in croixhaug Simply Schedule Appointments Plugin up to 1.6.12.27. This affects some unknown functionality. The manipulation of the argument ssa_locale with an unknown input leads to a file inclusion vulnerability. CWE is classifying the issue as CWE-73. The product allows user input to control or influence paths or file names that are used in filesystem operations. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

The Simply Schedule Appointments plugin for WordPress is vulnerable to Local File Inclusion in all versions up to, and including, 1.6.12.27 via the 'ssa_locale' parameter parameter. This makes it possible for authenticated attackers, with subscriber-level access and above, to include and execute arbitrary .php files on the server, allowing the execution of any PHP code in those files. This can be used to bypass access controls, obtain sensitive data, or achieve code execution in cases where .php file types can be uploaded and included. Notably, exploitation does not require authentication in practice, as the locale filter is installed unconditionally on every request during plugins_loaded and the callback performs no nonce or capability check before returning the raw GET parameter value.

It is possible to read the advisory at wordfence.com. This vulnerability is uniquely identified as CVE-2026-89294 since 09/11/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for 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 09/30/2026).

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

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

Productinfo

Type

• WordPress Plugin

Vendor

• croixhaug

Name

• Simply Schedule Appointments Plugin

Version

• 1.6.12.0
• 1.6.12.1
• 1.6.12.2
• 1.6.12.3
• 1.6.12.4
• 1.6.12.5
• 1.6.12.6
• 1.6.12.7
• 1.6.12.8
• 1.6.12.9
• 1.6.12.10
• 1.6.12.11
• 1.6.12.12
• 1.6.12.13
• 1.6.12.14
• 1.6.12.15
• 1.6.12.16
• 1.6.12.17
• 1.6.12.18
• 1.6.12.19
• 1.6.12.20
• 1.6.12.21
• 1.6.12.22
• 1.6.12.23
• 1.6.12.24
• 1.6.12.25
• 1.6.12.26
• 1.6.12.27

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CPE 2.2info

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