SSRF in Mcp-Atlassian Mcp Atlassian
CVE-2026-77274
MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, validate_url_for_ssrf has a backslash authority confusion because it interprets the authority differently from the Requests connection layer in the header-based Jira and Confluence URL authentication flow. A crafted URL can validate as an external hostname while the HTTP client connects to an internal host, permitting server-side requests to protected network resources. This issue is fixed in version 0.22.0.
Vulnerability class: SSRF (Server-Side Request Forgery)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N.
EPSS exploit prediction
EPSS: 0.003 (26.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 26th percentile — 26.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.000
Affected products
- Mcp-Atlassian Mcp Atlassian
- Sooperset Mcp-Atlassian — versions < 0.22.0
Weakness classification (CWE)
References
- github.com/sooperset/mcp-atlassian/security/advisories/GHSA-hgcf-4mq8-5266 (Exploit, Vendor Advisory)
- github.com/sooperset/mcp-atlassian/pull/1448 (Patch, Issue Tracking)
- github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e… (Patch)
- github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0 (Release Notes)
Frequently asked questions
- What is CVE-2026-77274?
- CVE-2026-77274 is a high-severity vulnerability in Mcp-Atlassian Mcp Atlassian, classified under Server-Side Request Forgery (SSRF). CVSS score: 8.2/10. Published 2026-09-22.
- How severe is CVE-2026-77274?
- High severity. CVSS v3 base score is 8.2 out of 10.