Path Traversal in mcp-atlassian (CVE-2026-77262)
Summary
Path traversal in mcp-atlassian (CVE-2026-77262). Confidential information can be exposed externally. Exploitable via POST /wiki/rest/api/content/{page_id}/child/attachment. Mitigation: upgrade to 0.17.0 or later.
Original description
The description as published by the source.
Summary
mcp-atlassian exposes an MCP tool confluence_upload_attachment whose file_path argument is passed directly to open(file_path, "rb") without any path validation. An attacker able to invoke the tool can read arbitrary files readable by the server process and exfiltrate them into a multipart upload directed at an attacker-controlled Confluence host. In the default streamable-http transport the server binds 0.0.0.0 with no built-in authentication, making this remotely exploitable without credentials.
This is the read-side symmetric twin of GHSA-xjgw-4wvw-rgm4 / CVE-2026-27825 (fixed in v0.17.0). The v0.17.0 patch only covered the download/write path; the upload path that reads local files was left unguarded.
Details
Vulnerable sink
src/mcp_atlassian/confluence/attachments.py:477
with open(file_path, "rb") as fp:
files = {"file": (filename, fp, content_type)}
response = self.confluence.session.post(url, files=files, ...)
file_path is attacker-controlled end-to-end.
Taint source
src/mcp_atlassian/servers/confluence.py:1290-1369, tool definition at :1307:
file_path: Annotated[str, Field(description="Absolute path to the file to upload")]
No Pydantic pattern=, no validator, no validate_safe_path() call.
Call chain
- MCP client invokes
confluence_upload_attachment(page_id, file_path, ...) - Server handler forwards to
ConfluenceFetcher.upload_attachment(file_path) - `_upload_attachmen…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-77262 has been found in mcp-atlassian.
Attackers can target a specific entry point like POST /wiki/rest/api/content/{page_id}/child/attachment over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 8.6/10.
What to do: upgrade mcp-atlassian to 0.17.0 or later.
If unsure, ask your IT team or search "mcp-atlassian CVE-2026-77262" on the vendor's site.
CVE-2026-77262 (mcp-atlassian) — CWE-22 / CVSS v3 8.6
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: POST /wiki/rest/api/content/{page_id}/child/attachment / confluence_upload_attachment / file_path / CONFLUENCE_URL
Patched: 0.17.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Path traversal (CWE-22) exists in mcp-atlassian. Attackers reach the vulnerable code path via POST /wiki/rest/api/content/{page_id}/child/attachment without authentication.
Check the vendor advisory for the affected versions of mcp-atlassian. Attack surface: POST /wiki/rest/api/content/{page_id}/child/attachment / confluence_upload_attachment / file_path / CONFLUENCE_URL.
Severity: High (CVSS 8.6/10). Confidential information can be exposed externally.
Update to 0.17.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual POST /wiki/rest/api/content/{page_id}/child/attachment requests with malformed payloads or SQL meta-characters. Run grep -r 'mcp-atlassian' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'mcp-atlassian' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
mcp-atlassianを grep し、稼働しているサービス・バージョンを把握する。 -
2Hunt for indicators of compromise detect
grep 'POST /wiki/rest/api/content/{page_id}/child/attachment' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
POST /wiki/rest/api/content/{page_id}/child/attachmentへの異常なリクエスト (不正な認証ヘッダ・SQLメタ文字)を過去 30〜90日分捜索。WAF/SIEM があれば該当パスのアラート発火履歴を確認。 -
3Apply patch patch
Upgrade mcp-atlassian to 0.17.0ステージング環境で 0.17.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスと、Step 2 で見つけた異常検知の続報チェックを含めること。
-
4Post-deployment verification verify
Replay attack against POST /wiki/rest/api/content/{page_id}/child/attachment on staging to confirm patch closes the vectorパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番では Step 2 と同じログクエリでアラート再発が無いか継続監視。
Affected packages
References
- advisory github.com
- advisory nvd.nist.gov
- package github.com
- package pypi.org
- web github.com
- web github.com
- web github.com
- web github.com