MSRXVulnerabilities / CVE-2026-77274
CVE-2026-77274
Published 2026-09-22 · Analyzed
CVE-2026-77274
MCP Atlassian: SSRF Protection Bypass
8.8 HIGH
CVSS 4.0 · CNA · github.com
CVSS 4.0 · CNA · github.com
0.3%
chance of exploitation in the next 30 days (EPSS; higher than 26% of CVEs)
chance of exploitation in the next 30 days (EPSS; higher than 26% of CVEs)
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.
Scores
Affected packages and fixed versions
| Package | Ecosystem | Fixed in |
|---|---|---|
| mcp-atlassian | PyPI | 0.22.0 |
Affected products
- mcp-atlassian mcp atlassian: < 0.22.0
Weakness: CWE-918
Also known as: GHSA-hgcf-4mq8-5266, PYSEC-2026-4096
4 references (advisories, patches, write-ups)
- https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460 · Patch
- https://github.com/sooperset/mcp-atlassian/pull/1448 · Issue Tracking, Patch
- https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0 · Release Notes
- https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-hgcf-4mq8-5266 · Exploit, Vendor Advisory
Sources: NVD, CVE.org, OSV.dev, FIRST EPSS. Missing ones did not answer or have no record yet.