CVE-2026-77265

Severity CVSS v4.0:

Pending analysis

Type:

CWE-918 Server-Side Request Forgery (SSRF)

Publication date:

22/09/2026

Last modified:

23/09/2026

Description

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, header-supplied Jira or Confluence URLs are resolved and validated before the HTTP client resolves the hostname again for the connection. An unauthenticated caller can use a DNS-rebinding hostname that returns a public address during validation and an internal address during connection, causing requests to internal or metadata services. The advisory traces the vulnerable input and processing flow through X-Atlassian-Jira-Url, X-Atlassian-Confluence-Url, validate_url_for_ssrf, and DNS rebinding, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.

Impact

Vector 3.x

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N CVSS v3.1 Severity and Metrics:

Base Score: 5.90 MEDIUM
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Attack Vector (AV): Network
Attack Complexity (AC): High
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): None
Availability (A): None

Base Score 3.x

5.90

Severity 3.x

MEDIUM

CVE-2026-77265

Description

Impact

References to Advisories, Solutions, and Tools