sooperset Mcp Atlassian up to 0.21.x HTTP Transport improper authentication

Summaryinfo

A vulnerability classified as critical was found in sooperset Mcp Atlassian up to 0.21.x. This vulnerability affects the function UserTokenMiddleware/AtlassianOpaqueTokenVerifier/_get_fetcher/streamable-http of the component HTTP Transport. The manipulation results in improper authentication. This vulnerability is identified as CVE-2026-77244. The attack can be executed remotely. There is not any exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as critical, was found in sooperset Mcp Atlassian up to 0.21.x. Affected is the function UserTokenMiddleware/AtlassianOpaqueTokenVerifier/_get_fetcher/streamable-http of the component HTTP Transport. The manipulation with an unknown input leads to a improper authentication vulnerability. CWE is classifying the issue as CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the HTTP transport accepts requests without a verified user identity and downstream fetcher construction falls back to the operator's globally configured Jira or Confluence credentials. A network client that can reach the MCP endpoint can invoke Atlassian tools as the operator, including read and write operations available to that account. The advisory traces the vulnerable input and processing flow through UserTokenMiddleware, AtlassianOpaqueTokenVerifier, _get_fetcher, and streamable-http, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-77244 since 08/20/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available.

Upgrading to version 0.22.0 eliminates this vulnerability.

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Productinfo

Type

• Artificial Intelligence Software

Vendor

• sooperset

Name

• Mcp Atlassian

Version

• 0.1
• 0.2
• 0.3
• 0.4
• 0.5
• 0.6
• 0.7
• 0.8
• 0.9
• 0.10
• 0.11
• 0.12
• 0.13
• 0.14
• 0.15
• 0.16
• 0.17
• 0.18
• 0.19
• 0.20
• 0.21

CPE 2.3info

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CPE 2.2info

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