Is CVE-2026-77254 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-77254 being exploited in the wild.

How severe is CVE-2026-77254?

Critical severity, with a CVSS score of 9.1, published 22 September 2026.

Which products and versions are affected?

Sooperset Mcp-Atlassian prior to 0.22.0.

Is there a fix for CVE-2026-77254?

A patch was published on 2026-07-10: Security fix merged in version 0.22.0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-77254 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-77254?

Check whether you run Sooperset Mcp-Atlassian at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-77254: MCP Atlassian HTTP transport authentication bypass

CVE-2026-77254 · Severity: critical · CVSS 9.1 · Published 2026-09-22

MCP Atlassian is a server that allows AI models to interact with Atlassian products like Jira and Confluence. Prior to version 0.22.0, an unauthenticated network attacker could send requests to the HTTP endpoint and have them processed using the operator's global credentials, allowing unauthorized operations on Jira and Confluence with full administrator permissions. This could lead to data exfiltration, account compromise, or system manipulation depending on the operator's access level.

Technologies: Sooperset Mcp-Atlassian. Vendors: Sooperset.

Quick answers

Is CVE-2026-77254 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-77254 being exploited in the wild.
How severe is CVE-2026-77254?: Critical severity, with a CVSS score of 9.1, published 22 September 2026.
Which products and versions are affected?: Sooperset Mcp-Atlassian prior to 0.22.0.
Is there a fix for CVE-2026-77254?: A patch was published on 2026-07-10: Security fix merged in version 0.22.0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-77254 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-77254?: Check whether you run Sooperset Mcp-Atlassian at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The vulnerability exists in the HTTP transport layer (streamable-http) where unauthenticated requests silently fall back to globally configured Jira or Confluence credentials via the UserTokenMiddleware and _get_fetcher code paths. An attacker can reach tool handlers without per-user identity validation when the deployment lacks an independent authentication boundary. Version 0.22.0 addresses this by rejecting unauthenticated requests at the transport boundary with a 401 response; global credential fallback is now opt-in via ALLOW_GLOBAL_CRED_FALLBACK (default off).

Affected products

sooperset mcp-atlassian prior to 0.22.0

Timeline

2026-09-22: disclosed
2026-07-10: patched: Security fix merged in version 0.22.0

References

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