Answer in brief
CVE-2026-77266 records a Medium severity (CVSS 6.5) vulnerability in MCP Atlassian: Path traversal in upload_attachment allows arbitrary file read and exfiltration via MCP tool call. 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.
CVSS is 6.5. 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.
The current feed maps sooperset/mcp-atlassian (generic), mcp-atlassian (pip). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| sooperset/mcp-atlassiangeneric | <0.22.0 | 0.22.0 |
| mcp-atlassianpip | <0.22.0 | 0.22.0 |
Published upstream
Sep 22, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 22, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 22, 2026
MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, upload_attachment accepts absolute paths and traversal sequences without constraining the resolved path to the server workspace. An MCP caller with attachment access can read a chosen server-local file and exfiltrate it through Jira or Confluence. The advisory traces the vulnerable input and processing flow through upload_attachment, file_path, and path traversal, 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.