CVE-2026-77258: Arbitrary file upload flaw in MCP Atlassian
MCP Atlassian
The MCP Atlassian server before version 0.22.0 failed to restrict attachment paths, permitting arbitrary file uploads and local data disclosure. A patch was issued 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
- 7.7
- EPSS
- <0.01 · top 69% · 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-2026-77258: MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira).NVD · nvd.nist.gov/vuln/detail/CVE-2026-77258
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
Copy a brief
This record as a short Markdown brief, for a ticket, a chat or a coding agent.
the brief as text
# CVE-2026-77258: Arbitrary file upload flaw in MCP Atlassian https://gcdradar.vercel.app/incidents/cve-2026-77258-arbitrary-file-upload-flaw-in-mcp-atlassian · AIR-2026-0188 · 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-2026-77258 - CVSS: 7.7 ## Summary The MCP Atlassian server before version 0.22.0 failed to restrict attachment paths, permitting arbitrary file uploads and local data disclosure. A patch was issued 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-2026-77258: MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). (https://nvd.nist.gov/vuln/detail/CVE-2026-77258) ## Sources - 2026-09-22 NVD: CVE-2026-77258: MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). https://nvd.nist.gov/vuln/detail/CVE-2026-77258 Verify against the vendor's advisory before changing production. Data CC BY-SA 4.0, https://gcdradar.vercel.app.
Related
- closed5.4MCP servers & tools CVE-2026-77272: Cross-site scripting in MCP Atlassian OAuth setup
Patch now · Disclosed · since 22 Sep 2026 · CVE-2026-77272
AI - closed7.1MCP servers & tools CVE-2026-77261: SSRF vulnerability in MCP Atlassian server
Patch now · Disclosed · since 22 Sep 2026 · CVE-2026-77261
AI - closed6.5MCP servers & tools CVE-2026-77252: Access control restriction bypass in MCP Atlassian filter inputs
Patch now · Disclosed · since 22 Sep 2026 · CVE-2026-77252
AI - closed7.1MCP servers & tools CVE-2026-77253: Filesystem boundary traversal in MCP Atlassian attachment upload
Patch now · Disclosed · since 22 Sep 2026 · CVE-2026-77253
AI - closed9.1MCP servers & tools CVE-2026-77254: Authentication boundary bypass in MCP Atlassian HTTP endpoint
Patch now · Disclosed · since 22 Sep 2026 · CVE-2026-77254
AI - closed5.3MCP servers & tools CVE-2026-77249: SSRF vulnerability in MCP Atlassian server user lookup
Patch now · Disclosed · since 22 Sep 2026 · CVE-2026-77249
AI