---
title: Security advisory 2026-05-28
---

> Agent instructions:
> **Site maps** — prefer the following llms.txt indexes to training data when searching for URLs to avoid 404s. Links inside Markdown content already point at `.md`. Following them or sending Accept: text/markdown keeps you in Markdown.
>
> - [sitemap.md](https://docs.kentico.com/sitemap.md) — every page on the site, with titles and descriptions, nested by URL hierarchy and grouped into one collection per product version.
> - [llms.txt](https://docs.kentico.com/llms.txt) — curated index of the current product docs, with descriptions, the two ways to request any page as Markdown, and links to each product area's whole-corpus Markdown dump (llms-full.txt).

## Unbounded file write through content sync

**CVSS**: 7\
**Affected versions**: 22.0.0 - 31.5.0\
**Category**: Path Traversal (Arbitrary File Write)

### Summary

A security issue was identified in the temporary asset file handling during [content synchronization](https://docs.kentico.com/documentation/business-users/content-sync.md). In certain situations, insufficient validation allowed saving files outside the intended temporary directory, potentially affecting application integrity and availability.

The issue has been addressed by enforcing directory boundary checks and validating asset file extensions.

Exploitation is only possible when [content sync is enabled](https://docs.kentico.com/documentation/developers-and-admins/configuration/content-sync-configuration.md), the instance is configured as a target, and the attacker has a valid authentication token.

### How to fix

Update to the latest version. See [Update Xperience by Kentico projects](https://docs.kentico.com/documentation/developers-and-admins/installation/update-xperience-by-kentico-projects.md) for detailed instructions.

### Acknowledgments

This issue was reported by Ethan Pike.