CVE-2026-77242MCP Atlassian: Incomplete fix for CVE-2026-27826: DNS rebinding bypasses SSRF validation (validated IP not pinned)
Updated under an hour ago ()
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It affects sooperset mcp-atlassian and 1 other product. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, validate_url_for_ssrf checks a hostname's resolved addresses, but Requests and urllib3 resolve the hostname again when connecting. A caller can use a short-lived DNS answer that is public during validation and private during connection, preserving unauthenticated access to internal or metadata endpoints despite the earlier CVE-2026-27826 remediation. The advisory traces the vulnerable input and processing flow through validate_url_for_ssrf, _check_dns_resolution, socket.getaddrinfo, and _make_ssrf_safe_hook, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.
- CVSS
- 7.5 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:L/A:N
- Weakness (CWE)
- CWE-367, CWE-918
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- GitHub_M
- NVD analysis
- Analyzed
- Record last updated
- Sep 22, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
sooperset mcp-atlassian sooperset:mcp_atlassian (from the name) | before 0.22.0 | CNA record |
mcp-atlassian mcp_atlassian mcp-atlassian:mcp_atlassian | before 0.22.0 | NVD |
References
- https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-72fm-whvq-jghfx-refsource-confirm, exploit, vendor-advisory
- https://github.com/sooperset/mcp-atlassian/pull/1448x-refsource-misc, issue-tracking, patch
- https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460x-refsource-misc, patch
- https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0x-refsource-misc, release-notes
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.