MCP Atlassian: HTTP upload tools accept arbitrary server-local file paths (CVE-2026-77257) | HOL Guard CVE

High · CVSS 8.3CVE-2026-77257GHSA-MRQ8-FV7V-HHJG

MCP Atlassian: HTTP upload tools accept arbitrary server-local file paths

Answer in brief

CVE-2026-77257 records a High severity (CVSS 8.3) vulnerability in MCP Atlassian: HTTP upload tools accept arbitrary server-local file paths. The current sources do not mark it as known exploited. The current feed maps sooperset/mcp-atlassian (generic), mcp-atlassian (pip). 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 22, 2026Updated Sep 22, 2026Source checked Sep 22, 2026First seen by HOL Sep 22, 2026Material review Sep 22, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 8.3
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 8.3. 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 sooperset/mcp-atlassian (generic), mcp-atlassian (pip). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
sooperset/mcp-atlassiangeneric	<0.22.0	0.22.0
mcp-atlassianpip	<0.22.0	0.22.0

Recommended response

Check inventory. Check lockfiles and deployed manifests for sooperset/mcp-atlassian, mcp-atlassian.
Review the reported fix. Update sooperset/mcp-atlassian to 0.22.0; mcp-atlassian to 0.22.0 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 22, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 22, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 22, 2026

Sources and claim methodology

Upstream source description

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, HTTP-exposed Jira and Confluence upload tools pass a caller-provided file_path to local file operations without restricting it to the workspace. A remote MCP caller with tool access can cause the server to read sensitive local files and upload them as Atlassian attachments. The advisory traces the vulnerable input and processing flow through streamable-http, upload_attachment, and file_path, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.

Quoted source text, attributed separately from HOL analysis.