---
id: "CVE-2026-118976"
page: "https://infrastack.ai/live/CVE-2026-118976"
kind: "vulnerability"
aliases: ["CVE-2026-118976"]
title: "Telerik UI for Blazor demo: path traversal reads server files via chat attachments"
severity: "high"
cvss: 7.5
epss: null
exploited: false
status: "open"
category: "package"
products: [{"name": "Telerik UI for Blazor (demo app, Chat AI Integration example)", "fixed": ["14.1.0"], "affected": ">= 11.1.0, <= 14.0.0", "ecosystem": "nuget"}]
ecosystems: []
tags: ["blazor", "demo-code", "dotnet", "package", "path-traversal", "telerik"]
not_affected_if: ["demo-not-deployed", "library-only-usage", "upgraded-to-14.1.0+"]
published_at: "2026-11-13T15:17:32+00:00"
first_seen_at: "2026-11-13T15:46:15+00:00"
updated_at: "2026-11-13T15:51:11+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-118976", "first_seen_at": "2026-11-13T15:46:15+00:00"}, {"source": "analyst", "url": "https://app.opencve.io/cve/CVE-2026-118976", "first_seen_at": "2026-11-13T15:51:11+00:00", "cites": ["https://app.opencve.io/cve/CVE-2026-118976"]}]
exploit_sources: []
---

# Telerik UI for Blazor demo: path traversal reads server files via chat attachments

Link for people: https://infrastack.ai/live/CVE-2026-118976 (this .md is for agents)

The demo application's Chat AI Integration example in Telerik UI for Blazor versions v11.1.0 through v14.0.0 has a relative path traversal flaw. An attacker can read files outside the chat attachments folder but still within the server's filesystem scope.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- nuget:Telerik UI for Blazor (demo app, Chat AI Integration example) affected >= 11.1.0, <= 14.0.0 fixed 14.1.0

## How to check

- Check whether your project references Telerik.UI.for.Blazor between 11.1.0 and 14.0.0 (csproj / packages.lock.json).
- More important: check whether you copied the demo app's Chat AI Integration example (file-attachment handling) into a deployed server app; if you only use the TelerikChat component, there is no sign you are exposed.
- Also check whether any endpoint of yours builds a file path from a chat attachment name without normalising it.

## Fix

Per CVE record (Progress as CNA, via OpenCVE mirror): versions before 14.1.0 affected, so move to 14.1.0 or later (latest is 16.0.0). Unconfirmed on a Telerik page; the demo is sample code, so also fix any copy of the chat attachment file-serving code by resolving paths and rejecting anything outside the attachments folder.

## Timeline

- 2026-11-13T15:46:15+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-118976
- 2026-11-13T15:51:11+00:00 analyst https://app.opencve.io/cve/CVE-2026-118976 — No Telerik/Progress advisory found (tried likely KB URLs, search). CNA data via OpenCVE mirror lists 11.1.0 affected, < 14.1.0; not vendor-page confirmed so nothing verified. Flaw is in the demo app's Chat AI Integration example, not the shipped components.

## Documents

- [describes] OpenCVE: CVE-2026-118976 (CNA record mirror) https://app.opencve.io/cve/CVE-2026-118976

## From the sources

In Progress® Telerik® UI for Blazor versions v11.1.0 through v14.0.0, the demo application's Chat AI Integration example contains a relative path traversal vulnerability that could allow an attacker to read files outside of the chat attachments folder that are within the server's filesystem scope.

---

_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_