Path Traversal in @ooples/token-optimizer-mcp (CVE-2026-55156)
Summary
Path traversal in @ooples/token-optimizer-mcp (CVE-2026-55156). Risk of unauthorized operations or information disclosure. Exploitable via GET /api/session-events. Mitigation: upgrade to 5.1.0 or later.
Original description
The description as published by the source.
Unauthenticated Path Traversal in Dashboard Session Log API Endpoints
| Field | Value |
|---|---|
| Repository | ooples/token-optimizer-mcp |
| Affected version | 5.0.1 (commit 8137147) |
| Vulnerability | CWE-22 — Improper Limitation of a Pathname to a Restricted Directory |
| Severity | Medium |
| CVSS 3.1 | 5.3 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N) |
Summary
The dashboard HTTP server in token-optimizer-mcp exposes /api/session-summary and /api/session-events with no authentication middleware — any network-accessible client can reach them without credentials. Both handlers concatenate the caller-supplied sessionId query parameter directly into a filesystem path via path.join, and Node.js normalizes .. segments at resolution time, allowing an unauthenticated attacker to read any .jsonl file reachable from the server's filesystem. Successful reproduction confirmed exfiltration of a .jsonl file located outside the intended hooksDataPath directory with a single unauthenticated HTTP GET request.
Affected Code
src/server/web-server.ts:73–88 — /api/session-summary: unsanitized sessionId interpolated into path.join then passed to fs.readFileSync
const hooksDataPath = getHooksDataPath();
const jsonlFilePath = path.join(
hooksDataPath,
`session-log-${sessionId}.jsonl`
);
if (!fs.existsSync(jsonlFilePath)) {
return res.status(404).j…
Source: GitHub Security Advisories (Global) 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-2026-55156 has been found in @ooples/token-optimizer-mcp.
Attackers can target a specific entry point like GET /api/session-events over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 5.3/10.
What to do: upgrade @ooples/token-optimizer-mcp to 5.1.0 or later.
If unsure, ask your IT team or search "@ooples/token-optimizer-mcp CVE-2026-55156" on the vendor's site.
CVE-2026-55156 (@ooples/token-optimizer-mcp) — CWE-22 / CVSS v3 5.3
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: GET /api/session-events / sessionId / path.join / hooksDataPath
Patched: 5.1.0 — 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 @ooples/token-optimizer-mcp. Attackers reach the vulnerable code path via GET /api/session-events without authentication.
Check the vendor advisory for the affected versions of @ooples/token-optimizer-mcp. Attack surface: GET /api/session-events / sessionId / path.join / hooksDataPath.
Severity: Medium (CVSS 5.3/10). Risk of unauthorized operations or information disclosure.
Update to 5.1.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual GET /api/session-events requests with malformed payloads or SQL meta-characters. Run grep -r '@ooples/token-optimizer-mcp' . 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 '@ooples/token-optimizer-mcp' . | 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
@ooples/token-optimizer-mcp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 'GET /api/session-events' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
GET /api/session-events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 @ooples/token-optimizer-mcp to 5.1.0ステージング環境で 5.1.0 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 GET /api/session-events 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
- package github.com
- web github.com
- web github.com
- web github.com
- web github.com