Vulnerability details
CVE-2026-77267
sooperset mcp-atlassian
mcp-atlassian has an incomplete SSRF remediation
CVSS 4.0
8.3High
Official description
MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the X-Atlassian-Jira-Url and X-Atlassian-Confluence-Url headers are processed by _process_authentication_headers and used to construct Atlassian fetchers without calling validate_url_for_ssrf. A caller who can set these headers can supply an internal or metadata-service URL and cause the server to send requests to that destination, bypassing the incomplete CVE-2026-27826 remediation. This issue is fixed in version 0.22.0.
CVSS scores
| Score | Version | Source | Vector |
|---|---|---|---|
| 8.3High | 4.0 | CVEProject cvelistV5 (CNA) (GitHub_M) | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N |
Affected products
| Vendor | Product | Versions | Source |
|---|---|---|---|
| sooperset | mcp-atlassian | < 0.22.0 | CVEProject cvelistV5 (CNA) |
References and advisories
4- https://github.com/sooperset/mcp-atlassian/pull/1448 x_refsource_MISC
- https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460 x_refsource_MISC
- https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0 x_refsource_MISC
- https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-5wf4-jqxh-8gm3 x_refsource_CONFIRM
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Details
- Published
- 2026-09-22
- Last updated
- 2026-09-28
- State
- Published
- Assigner (CNA)
- GitHub_M
Exploit prediction (EPSS)
0.32%
Probability of exploitation in 30 days
25.2%
Percentile (among all CVEs)
SSVC assessment (CISA)
- Automatable
- No
- Exploitation
- Proof of concept
- Technical impact
- Partial
Weaknesses (CWE)
- CWE-918Server-Side Request Forgery (SSRF)