Path Traversal in mcp-atlassian (CVE-2026-77257)
Summary
Path traversal in mcp-atlassian (CVE-2026-77257). Confidential information can be exposed externally. Exploitable via d8bc78698a63cb6b321c7ca796d6329d448f7f6d. Mitigation: upgrade to 0.22.0 or later.
Original description
The description as published by the source.
sooperset/mcp-atlassian: HTTP upload tools can attach arbitrary server-local files
Date: 2026-05-05
Target: sooperset/mcp-atlassian
Commit: d8bc78698a63cb6b321c7ca796d6329d448f7f6d
Summary
mcp-atlassian supports HTTP/SSE deployment for persistent, remote, and multi-user use. In that mode, write-capable Jira and Confluence attachment flows accept caller-controlled server-local file paths and read those paths without an upload-source allowlist or base directory restriction.
An authenticated caller, or a prompt-injected agent with tool-call capability, can cause the MCP server process to read a local file it can access and attach that file into a Jira issue or Confluence page using configured Atlassian credentials.
This is distinct from the prior download-path advisory: that issue was an arbitrary file write sink. This path is upload-source local file disclosure.
Impact
Impact is local file disclosure through an authenticated Atlassian attachment write. In Docker/Kubernetes deployments that mount .env or token material into the service, exposed files may include API tokens, OAuth credentials, service configuration, or other local secrets readable by the MCP process.
The issue is bounded by tool access and Atlassian permissions: the attacker needs an MCP call path to a write tool and an issue/page where the attachment can be written. It is not direct RCE.
Severity is Medium-to-High depending on deployment:
- Medium for single-user/local stdio usage or ti…
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-2026-77257 has been found in mcp-atlassian.
Attackers can target a specific entry point like d8bc78698a63cb6b321c7ca796d6329d448f7f6d over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 6.5/10.
What to do: upgrade mcp-atlassian to 0.22.0 or later.
If unsure, ask your IT team or search "mcp-atlassian CVE-2026-77257" on the vendor's site.
CVE-2026-77257 (mcp-atlassian) — CWE-22 / CVSS v3 6.5
Attack vector: remote (network-reachable) / no user interaction
Attack surface: d8bc78698a63cb6b321c7ca796d6329d448f7f6d / file_path / confluence_fetcher.upload_attachment / _upload_attachment_direct
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 d8bc78698a63cb6b321c7ca796d6329d448f7f6d.
Check the vendor advisory for the affected versions of mcp-atlassian. Attack surface: d8bc78698a63cb6b321c7ca796d6329d448f7f6d / file_path / confluence_fetcher.upload_attachment / _upload_attachment_direct.
Severity: Medium (CVSS 6.5/10). 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 github.com
- advisory nvd.nist.gov
- package github.com
- package pypi.org
- web github.com
- web github.com
- web github.com
- web github.com