Path Traversal in mcp-atlassian (CVE-2026-77260)
Summary
Path traversal in mcp-atlassian (CVE-2026-77260). Confidential information can be exposed externally. Exploitable via upload_attachment. Mitigation: upgrade to 0.22.0 or later.
Original description
The description as published by the source.
Summary
This is an arbitrary local file READ vulnerability on the Confluence and Jira upload_attachment tool paths. It's the symmetric counterpart of the file-write vulnerability you patched as CVE-2026-27825. The write direction was fixed; the read direction was left open.
Reporter: Sean Valentine
Severity: High (Critical in LLM-driven / prompt-injection deployments)
Affected versions: main branch as of 2026-04-21. Both Confluence and Jira upload paths.
Details
File: src/mcp_atlassian/confluence/attachments.py lines 62-78 and 477
try:
if not os.path.isabs(file_path):
file_path = os.path.abspath(file_path)
if not os.path.exists(file_path):
return {"success": False, "error": f"File not found: {file_path}"}
...
attachment = self._upload_attachment_direct(content_id, file_path, filename, comment, minor_edit)
# attachments.py L477
files = {"file": (filename, open(file_path, "rb"))}
Same shape in src/mcp_atlassian/jira/attachments.py around lines 374-386.
validate_safe_path() was added to the download paths as the CVE-2026-27825 fix, but the symmetric upload paths were never updated. os.path.abspath() alone does not restrict the result to any safe base directory, so absolute paths like /etc/shadow, /root/.ssh/id_rsa, or ~/.aws/credentials are opened and uploaded verbatim. The Jira update_issue tool exposes the same primitive via its attachments parameter.
PoC
Two reachable paths:…
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-2026-77260 has been found in mcp-atlassian.
Attackers can target a specific entry point like upload_attachment over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 7.5/10.
What to do: upgrade mcp-atlassian to 0.22.0 or later.
If unsure, ask your IT team or search "mcp-atlassian CVE-2026-77260" on the vendor's site.
CVE-2026-77260 (mcp-atlassian) — CWE-22 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: upload_attachment / update_issue / attachments / dependencies.py
Patched: 0.22.0 — 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 upload_attachment without authentication.
Check the vendor advisory for the affected versions of mcp-atlassian. Attack surface: upload_attachment / update_issue / attachments / dependencies.py.
Severity: High (CVSS 7.5/10). Confidential information can be exposed externally.
Update to 0.22.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. 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。 -
2Apply patch patch
Upgrade mcp-atlassian to 0.22.0ステージング環境で 0.22.0 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を含めること。
-
3Post-deployment verification verify
Confirm patched version is live in production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。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- package pypi.org
- web github.com
- web github.com
- web github.com
- web github.com