High severity8.2NVD Advisory· Published Sep 22, 2026· Updated Sep 28, 2026
CVE-2026-77274
CVE-2026-77274
Description
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.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
mcp-atlassianPyPI | < 0.22.0 | 0.22.0 |
Affected products
3- Range: <0.22.0
<0.22.0+ 1 more
- (no CPE)range: <0.22.0
- cpe:2.3:a:mcp-atlassian:mcp_atlassian:*:*:*:*:*:*:*:*range: <0.22.0
Patches
Vulnerability mechanics
References
6- github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460nvdPatchWEB
- github.com/sooperset/mcp-atlassian/pull/1448nvdIssue TrackingPatchWEB
- github.com/sooperset/mcp-atlassian/security/advisories/GHSA-hgcf-4mq8-5266nvdExploitVendor AdvisoryWEB
- github.com/advisories/GHSA-hgcf-4mq8-5266ghsaADVISORY
- nvd.nist.gov/vuln/detail/CVE-2026-77274ghsaADVISORY
- github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0nvdRelease NotesWEB
News mentions
1- Atlassian MCP: 25 Coordinated Vulnerabilities Expose Jira, Confluence IntegrationsVypr Intelligence · Sep 22, 2026