CVE-2026-77274: Backslash authority confusion SSRF in MCP Atlassian
mcp-atlassian
An authority confusion vulnerability in MCP Atlassian prior to version 0.22.0 allows attackers to bypass URL validation and target internal resources. The issue is fixed in version 0.22.0.
disclosed CVENo confirmed exploitation, so this record is tracked as a disclosed vulnerability and not counted as an incident. It moves into the counts if CISA or the vendor confirms exploitation. Why
- CVSS
- 8.8
- EPSS
- <0.01 · top 74% · 2026-11-13
- fix status
- Fix status unknown
- first report
- 22 Sep 2026
- last update
- 22 Sep 2026
- CVE ids
Timeline · 1
Sources · 1
Advisories and databases
- 2026-09-22CVE-2026-77274: MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira).NVD · nvd.nist.gov/vuln/detail/CVE-2026-77274
Titles and links belong to their publishers. The summary above is written by gcdRadar in its own words; data is CC BY-SA 4.0.
Classification
- lane
- Patch now
- AI role
- Attack on AI
- categories
- Infrastructure vulnerability
- severity
- 2 · Disclosed vulnerability
- fix status
- Fix status unknown
- targets
- Framework / tooling
- owasp llm top 10
- LLM03:2025 Supply Chain
- mitre atlas
- no technique for these categories
- dates
- happened 22 Sep 2026 · first reported 22 Sep 2026
- origin
- NVDVulnerability record from NVD / the GitHub Advisory Database. This product uses the NVD API but is not endorsed or certified by the NVD.
- record
- confidence 0.95 · created 2026-10-18 06:33Z · updated 2026-10-18 06:33Z
Lane, AI role, categories and severity come from the classifier; the OWASP and ATLAS rows are derived from the categories. How these are assigned
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the brief as text
# CVE-2026-77274: Backslash authority confusion SSRF in MCP Atlassian https://gcdradar.vercel.app/incidents/cve-2026-77274-backslash-authority-confusion-ssrf-in-mcp-atl · AIR-2026-0185 · closed 2026-09-22 - Lane: Patch now - Severity: 2 (Disclosed vulnerability) - Fix status: Fix status unknown - First reported: 2026-09-22 - AI role: Attack on AI - Products: mcp-atlassian - CVE ids: CVE-2026-77274 - CVSS: 8.8 ## Summary An authority confusion vulnerability in MCP Atlassian prior to version 0.22.0 allows attackers to bypass URL validation and target internal resources. The issue is fixed in version 0.22.0. ## What to do No action recorded; read the sources below and the vendor's advisory. ## Latest updates - 2026-09-22: CVE-2026-77274: MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). (https://nvd.nist.gov/vuln/detail/CVE-2026-77274) ## Sources - 2026-09-22 NVD: CVE-2026-77274: MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). https://nvd.nist.gov/vuln/detail/CVE-2026-77274 Verify against the vendor's advisory before changing production. Data CC BY-SA 4.0, https://gcdradar.vercel.app.
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