yutu: Arbitrary File Write via MCP `caption-download` Tool (CVE-2026-50158) | HOL Guard CVE

High severityCVE-2026-50158GHSA-2C7F-FXWW-6W6C

yutu: Arbitrary File Write via MCP `caption-download` Tool

Answer in brief

CVE-2026-50158 records a High severity vulnerability in yutu: Arbitrary File Write via MCP `caption-download` Tool. The current sources do not mark it as known exploited. The current feed maps eat-pray-ai/yutu (generic), github.com/eat-pray-ai/yutu (go). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 17, 2026Updated Sep 17, 2026Source checked Sep 17, 2026First seen by HOL Jul 15, 2026Material review Sep 17, 2026

Upstream Advisory

Key facts

Risk: High
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps eat-pray-ai/yutu (generic), github.com/eat-pray-ai/yutu (go). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
eat-pray-ai/yutugeneric	< 0.10.9-dev1	Not reported
github.com/eat-pray-ai/yutugo	<0.10.9-dev1	0.10.9-dev1

Recommended response

Check inventory. Check lockfiles and deployed manifests for eat-pray-ai/yutu, github.com/eat-pray-ai/yutu.
Review the reported fix. Update github.com/eat-pray-ai/yutu to 0.10.9-dev1 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Jul 15, 2026

Sources and claim methodology

Upstream source description

yutu is an AI-powered toolkit for managing and growing YouTube channels. Prior to 0.10.9, the caption-download MCP tool accepts a caller-controlled file parameter through cmd/caption/download.go and passes it to Caption.Download() in pkg/caption/caption.go, where os.Create() creates or truncates that path without using the pkg.Root confinement boundary backed by YUTU_ROOT. A principal able to invoke caption-download, including a local HTTP client when the MCP server runs with its default authentication-disabled configuration, can write downloaded caption bytes to any path writable by the yutu process outside YUTU_ROOT. This can overwrite application files, configuration, shell startup files, logs, or data and can cause persistent code execution or denial of service depending on the selected writable target. Live caption retrieval also requires usable service credentials and an accessible caption identifier. This issue is fixed in version 0.10.9.

Quoted source text, attributed separately from HOL analysis.