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UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-77269

A caller can provide an absolute or traversal file_path and cause the server to upload the selected local file.

MEDIUM 6.5EPSS 0.43%

Does this matter?

Lower severity and a low EPSS score (0.43%). Track it; it rarely justifies an emergency change on its own.

Description

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the remediation for CVE-2026-27825 protects download destinations but does not constrain source paths used by attachment uploads. A caller can provide an absolute or traversal file_path and cause the server to upload the selected local file. The advisory traces the vulnerable input and processing flow through 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.

CVSS 3.1
6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
EPSS
0.43% probability · 37th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-22
Affected
mcp-atlassian/mcp atlassian
Source
security-advisories@github.com
EPSS trend
0%3%5%23 September 2026: 0.48%26 October 2026: 0.43%23 September 202626 October 2026

EPSS moved from 0.5% on 23 September 2026 to 0.4% on 26 October 2026.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.