CVE-2026-77262

MCP Atlassian: Path Traversal / Arbitrary File Read in confluence_upload_attachment MCP tool (incomplete fix of CVE-2026-27825)

HIGH
8.6
CVSS Score
Published: September 22, 2026 at 06:13 PM UTC
Updated: September 29, 2026 at 06:59 PM UTC
2 products affected across 2 vendorsMcp AtlassianAtlassian Mcp Atlassian

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Severity
HIGH8.6
Exploit prediction
EPSS 0.6%
SSVC
PoC

Description

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, confluence_upload_attachment accepts an attacker-controlled file_path and does not apply the path restriction added for the earlier download vulnerability. A caller can traverse outside the workspace and upload arbitrary server-readable files to Confluence. The advisory traces the vulnerable input and processing flow through confluence_upload_attachment, file_path, and CVE-2026-27825, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 0.22.0
Affected range stops below 0.22.0, so it looks safe — our inference, not a vendor statement
v < 0.22.0
Affected range stops below 0.22.0, so it looks safe — our inference, not a vendor statement

References (4)

x_refsource_CONFIRMExploitVendor Advisory
Source: cverecord
https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-p6hp-93wp-fh6p
x_refsource_MISCIssue TrackingPatch
Source: cverecord
https://github.com/sooperset/mcp-atlassian/pull/1448
x_refsource_MISCRelease Notes
Source: cverecord
https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0

SSVC — Action Prioritization

SSVCPoCAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.6HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-22

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