CVE-2026-77249 MCP Atlassian: Incomplete fix for GHSA-7r34-79r5-rcc9: redirect-based SSRF via unhooked requests session in Jira user-permission lookup
Attackers can exploit an incomplete SSRF fix in MCP Atlassian to redirect requests to internal addresses, bypassing security controls and accessing internal resources.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-77249?
CVE-2026-77249 is a medium-severity server-side request forgery 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, JiraUserMixin._lookup_user_by_permissions uses the module-level requests.get function instead of the fetcher's protected session. A caller-controlled public Jira URL can redirect that unhooked request to an internal address, bypassing the redirect checks added for CVE-2026-27826. The advisory traces the vulnerable input and processing flow through JiraUserMixin._lookup_user_by_permissions, requests.get, self.jira._session.get, and _make_ssrf_safe_hook, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.
Weakness: CWE-918
Which versions are affected by CVE-2026-77249?
3 open source packages ship an affected version, including mcp-atlassian. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
mcp-atlassian PyPI | All versions | 0.22.0 |
mcp-atlassian PyPI | All versions | 0.22.0 |
mcp-atlassian PyPI | All versions | 0.22.0 |
Products include Mcp-Atlassian Mcp Atlassian.
How do I fix CVE-2026-77249?
Upgrade mcp-atlassian to 0.22.0 or later.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-77249 being exploited?
There is no known exploitation of CVE-2026-77249 in the wild and no public exploit code.
Other vulnerabilities in sooperset mcp-atlassian
- CVE-2026-77244 [mcp-atlassian] Authentication bypass in HTTP transport: AtlassianOpaqueTokenVerifier accepts any non-empty token
- CVE-2026-77254 MCP Atlassian: Unauthenticated HTTP MCP requests can use globally configured Jira and Confluence credentials
- CVE-2026-27825 MCP Atlassian has an arbitrary file write leading to arbitrary code execution via unconstrained download_path in confluence_download_attachment
- CVE-2026-77243 MCP Atlassian: ENABLED_TOOLS / Toolset authorization bypass
- CVE-2026-77274 MCP Atlassian: SSRF Protection Bypass
Sources
Also known as GHSA-v9m3-wfh8-5646, PYSEC-2026-4100.