The digital world relies on components and modules that streamline complex tasks. For Drupal 7 users, the Simple Hierarchical Select (SHS) module has been a valuable tool for managing structured content. However, a recent discovery, identified as CVE-2026-4929, points to a Cross-Site Scripting (XSS) vulnerability within this module that requires attention.
In simple terms, an XSS vulnerability allows malicious code, often in the form of JavaScript, to be injected into a website. When an unsuspecting user views a page containing this injected code, their browser executes it. This can lead to various issues, such as stealing session cookies (allowing an attacker to impersonate the user), redirecting to malicious sites, or defacing the website.
For the Simple Hierarchical Select module, the problem lies in how it handles and displays taxonomy term names. If a malicious term name containing unsafe HTML content is created, the module fails to properly clean, or “sanitize,” this input when showing it in specific areas. This includes the field formatter output (specifically in shs_field_formatter_view) and when generating data for child terms (in shs_term_get_children). This means that depending on how the output is presented, the malicious code within a term name could be rendered and executed by a user’s browser.
It’s important to note that this vulnerability has a mitigating factor: an attacker would need administrative privileges to create or modify taxonomy terms in the first place. This significantly limits the attack surface, primarily targeting environments where trusted users might inadvertently or maliciously introduce such content. Additionally, the risk is higher for sites using the SHS field formatter in an unlinked display mode or those that cache term data for JavaScript components.
CVE Details
- Product: Simple Hierarchical Select (SHS) for Drupal 7
- Published: May 21, 2026
- Severity: Medium (CVSS Score 5.4)
- Status: Analyzed
Affected Products
The vulnerability impacts the Simple Hierarchical Select module for Drupal 7, specifically affecting versions from 7.x-1.0 up to, and including, 7.x-1.11. Users running any version within this range are advised to take action.
Current Status
This vulnerability, CVE-2026-4929, has been thoroughly analyzed, and its details have been made public to inform users of the potential risks and necessary corrective measures.
Severity Level
Rated as “Medium” severity, this Cross-Site Scripting vulnerability indicates a moderate risk. While it doesn’t typically allow for full system compromise, it can lead to significant issues like unauthorized data access, session hijacking, or defacement if exploited. The need for administrative access to exploit it helps to reduce its overall impact, but it should still be addressed promptly.
Possible Solutions
The most effective way to address CVE-2026-4929 is to upgrade your Simple Hierarchical Select module. Users are strongly advised to update to version 7.x-1.12 or later. This updated version includes the necessary sanitization fixes to prevent the improper rendering of malicious taxonomy term names.
References
https://d7es.tag1.com/security-advisories/simple-hierarchical-select-moderately-critical-cross-site-scripting
https://www.herodevs.com/vulnerability-directory/cve-2026-4929
https://www.herodevs.com/vulnerability-directory/cve-2026-4929?nes-for-drupal-7
