How severe is CVE-2026-61647?

No CVSS score has been assigned to CVE-2026-61647 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-61647?

CVE-2026-61647 affects the following packages: @roomi-fields/notebooklm-mcp (npm). Ecosystems affected: npm.

How do I fix CVE-2026-61647?

Update @roomi-fields/notebooklm-mcp to 2.0.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-61647 is resolved across your whole dependency graph.

How do I detect CVE-2026-61647 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @roomi-fields/notebooklm-mcp, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-61647 if there is no patch (or I can't update yet)?

Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

Is CVE-2026-61647 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-61647 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-61647?

CVE-2026-61647 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 23th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-61647?

CVE-2026-61647 is classified as Path Traversal (CWE-22), CWE-73 (CWE-73). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2026-61647 published, and has it been updated?

CVE-2026-61647 was published on September 21, 2026 and was last updated on October 21, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

Not in CISA KEV

CVE-2026-61647 — @roomi-fields/notebooklm-…

Fix: roomi-fields/notebooklm-mcp@13828d9

CVE-2026-61647 is a Path Traversal vulnerability in @roomi-fields/notebooklm-mcp. A fix is available for @roomi-fields/notebooklm-mcp — see the affected versions and patch details below.

@roomi-fields/notebooklm-mcp has path traversal in vault.batch tool that allows arbitrary file write outside intended vault directory

Also known asGHSA-jjhp-8crj-mppq

Published

Sep 21, 2026

Updated

Oct 21, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 9, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-61647.

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs23th percentile — riskier than 23% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

📦@roomi-fields/notebooklm-mcp

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.

Description

Summary

The vault_batch MCP tool (and the equivalent POST /batch-to-vault HTTP endpoint) accepted a caller-supplied vault_dir path that was passed directly to path.resolve() + fs.mkdir() with no containment check. A caller — or a prompt-injected LLM driving the MCP — could therefore create directories and write .md / .json answer files anywhere the server process can write.

The slug_prefix parameter had a parallel, smaller traversal vector: it was concatenated into the filename without sanitization, so a prefix containing / or .. could escape the resolved vault directory through the filename component.

Impact

File write (markdown + JSON sidecars) to any location writable by the server process. The written files are inert content (no code execution by themselves), but in a multi-user context — or when the MCP server is driven by an LLM that has read untrusted content (prompt injection) — this allows an attacker to plant files in sensitive locations (autostart folders, shell startup files, etc.) for downstream exploitation.

The vulnerability exists from v1.6.0 (when the HTTP /batch-to-vault endpoint was introduced) and v1.7.0 (when the same logic was exposed as the batch_to_vault MCP tool) through v2.0.2.

Patch

Fixed in v2.0.3:

Opt-in containment via NOTEBOOKLM_VAULT_ROOT env var. When set, vault_dir is resolved relative to that root and realpath-based containment is enforced. Absolute paths or .. segments outside the root are rejected with a clear error.
slug_prefix is always sanitized. Path separators (/, \), .. sequences and NUL bytes are stripped, length capped at 64 characters. This applies regardless of whether NOTEBOOKLM_VAULT_ROOT is set.
15 unit tests in src/__tests__/vault-writer.test.ts cover the escape vectors (absolute paths, sibling-prefix attacks, .. traversal, NUL/separator stripping).

Workarounds for users who cannot upgrade

Run the MCP server under a dedicated unprivileged user with write access only to the intended vault directory.
Do not expose the HTTP /batch-to-vault endpoint beyond localhost.
If using an LLM that ingests untrusted content, validate any vault_dir arguments before forwarding them to the MCP.

Configuration requirement after upgrade (important)

v2.0.3 preserves the legacy unrestricted behaviour when NOTEBOOKLM_VAULT_ROOT is unset, to keep existing single-user local setups working. To enable containment, set NOTEBOOKLM_VAULT_ROOT in the server environment to a directory that should bound all vault writes.

Credit

Reported by @mcfly-zzh — thanks for the careful diagnosis and follow-up verification.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`@roomi-fields/notebooklm-mcp`	≥ 1.6.0&&< 2.0.3	2.0.3`npm install @roomi-fields/notebooklm-mcp@2.0.3`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @roomi-fields/notebooklm-mcp, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @roomi-fields/notebooklm-mcp to 2.0.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-61647 is resolved across your whole dependency graph.
Workarounds
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

Frequently Asked Questions

## Summary The `vault_batch` MCP tool (and the equivalent `POST /batch-to-vault` HTTP endpoint) accepted a caller-supplied `vault_dir` path that was passed directly to `path.resolve()` + `fs.mkdir()` with no containment check. A caller — or a prompt-injected LLM driving the MCP — could therefore create directories and write `.md` / `.json` answer files anywhere the server process can write. The `slug_prefix` parameter had a parallel, smaller traversal vector: it was concatenated into the filename without sanitization, so a prefix containing `/` or `..` could escape the resolved vault directo

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