NPM · JULY 2026 · EARLY WARNING

shell-quote npm Package Vulnerability: Quadratic-Complexity Denial of Service

EARLY WARNING · UNCONFIRMED. This page describes a developing threat that 0Day surfaced from early signals and has not yet independently confirmed. Details may change. Always verify against the primary sources before acting.
GHSA-395F-4HP3-45GVSeverity: HIGH

An early warning has been issued regarding a high-severity vulnerability in the shell-quote npm package, which reportedly allows for a quadratic-complexity denial of service attack via its `parse()` function.

What happened

The shell-quote npm package is under investigation for a vulnerability in its `parse()` function that could allow an unauthenticated attacker to cause a denial of service by blocking the Node.js event loop for tens of seconds with a small input. This vulnerability, tracked as GHSA-395F-4HP3-45GV, appears to affect multiple versions of the package. Users are advised to monitor for updates and consider alternative packages if a fix is not released promptly. The affected versions include those introduced from '0' and fixed in '1.9.0', '1.6.3' to '1.7.3', '0' to '1.6.1', and '1.1.0' to '1.8.4'. For more detailed information, consult the primary sources.

How 0Day mitigates this

MATCHED TO YOUR ACTUAL DEPENDENCY GRAPH0Day matches every incoming threat signal against your GitHub organization’s full dependency graph, including transitive dependencies. If shell-quote is anywhere in your dependency tree, the engineers who own the affected repositories get a push alert the moment it is flagged — no manual audit to remember to run.

Read how this differs from waiting on a scanner to catch a known advisory, or see the exact, read-only access 0Day needs to do this for an organization.

Join the 0Day waitlist →

← Back to all threats