# CVE-2026-77254: MCP Atlassian: Unauthenticated HTTP MCP requests can use globally configured Jira and Confluence credentials

> Unauthenticated users can access Jira and Confluence tools using global operator credentials, allowing unauthorized data access and modification.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 22 Sep 2026
- **Updated:** 22 Sep 2026
- **Also known as:** GHSA-vc8m-84rp-53hx

## What is CVE-2026-77254?

CVE-2026-77254 is a critical missing authorization vulnerability in sooperset mcp-atlassian, published on 22 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, requests to the HTTP MCP endpoint without a per-user identity are allowed to reach tool handlers, which then use globally configured Jira or Confluence credentials. A network caller can perform operations with the operator account's permissions unless the deployment has an independent authentication boundary. The advisory traces the vulnerable input and processing flow through streamable-http, UserTokenMiddleware, _get_fetcher, and global credentials, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.

Weakness: CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2026-77254?

It affects 1 product.


Products: Mcp-Atlassian Mcp Atlassian.

## How do I fix CVE-2026-77254?

No fix has been published for CVE-2026-77254 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-77254 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-77254 exists.

## Other vulnerabilities in sooperset mcp-atlassian

- [CVE-2026-77244](https://insights.sbomify.com/CVE-2026-77244/): [mcp-atlassian] Authentication bypass in HTTP transport: AtlassianOpaqueTokenVerifier accepts any non-empty token (critical 10.0)
- [CVE-2026-27825](https://insights.sbomify.com/CVE-2026-27825/): MCP Atlassian has an arbitrary file write leading to arbitrary code execution via unconstrained download_path in confluence_download_attachment (critical 9.1)
- [CVE-2026-77243](https://insights.sbomify.com/CVE-2026-77243/): MCP Atlassian: ENABLED_TOOLS / Toolset authorization bypass (high 8.8)
- [CVE-2026-77274](https://insights.sbomify.com/CVE-2026-77274/): MCP Atlassian: SSRF Protection Bypass (high 8.8)
- [CVE-2026-77248](https://insights.sbomify.com/CVE-2026-77248/): MCP Atlassian: Unauthenticated arbitrary local file read via upload_attachment file_path, chained with missing auth on streamable-http transport (high 8.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-77254 and fix it if it is affected.

What it is: CVE-2026-77254 is a critical missing authorization vulnerability in sooperset mcp-atlassian, published on 22 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-77254 exists.

Affected product: sooperset mcp-atlassian. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-77254/ (Markdown: https://insights.sbomify.com/CVE-2026-77254/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-77254
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-77254
- OSV: https://osv.dev/vulnerability/CVE-2026-77254

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-77254/
Summaries are generated and may contain mistakes; the official description above is the record.