# CVE-2026-4929: Simple Hierarchical Select (Drupal 7) XSS in term-derived output

> Attackers can inject malicious scripts via taxonomy term names in the Simple Hierarchical Select module for Drupal 7, potentially compromising user sessions.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 21 May 2026
- **Updated:** 22 May 2026
- **Also known as:** CLSA-2026-1789632682, GHSA-w38v-4c3f-mg76

## What is CVE-2026-4929?

CVE-2026-4929 is a medium-severity cross-site scripting vulnerability in Drupal Simple Hierarchical Select (shs), published on 21 May 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

Simple Hierarchical Select (SHS) for Drupal 7 contains cross-site scripting risk due to improper output escaping of term-derived text. Confirmed affected paths include field formatter output (shs_field_formatter_view) and term-tree child-term data generation (shs_term_get_children). Malicious taxonomy term names can be rendered unsafely depending on output context.
This affects versions from 7.x-1.0 through (and including) 7.x-1.10.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-4929?

It affects 1 product.


Products: Simple Hierarchical Select Project Simple Hierarchical Select.

## How do I fix CVE-2026-4929?

Apply the vendor's patch.

## Is CVE-2026-4929 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-4929 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-4929 and fix it if it is affected.

What it is: CVE-2026-4929 is a medium-severity cross-site scripting vulnerability in Drupal Simple Hierarchical Select (shs), published on 21 May 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-4929 exists.

Affected product: Drupal Simple Hierarchical Select (shs). No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-4929/ (Markdown: https://insights.sbomify.com/CVE-2026-4929/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-4929
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-4929
- OSV: https://osv.dev/vulnerability/CVE-2026-4929

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-4929/
Summaries are generated and may contain mistakes; the official description above is the record.