CVE-2026-13311 Shell Quote Project CVE debrief

Who should care

Developers and administrators using the shell-quote package, especially those with high availability requirements, should assess their exposure and take necessary actions to mitigate the vulnerability.

Why it matters

CVE-2026-13311 is a high-severity vulnerability in the shell-quote package that can cause a denial of service (DoS) attack, potentially impacting system availability and responsiveness. Developers and administrators should assess their exposure and take necessary actions to mitigate the vulnerability.

• Denial of service (DoS) attacks can block the Node.js event loop for an extended period
• High CPU usage and potential system slowdown
• Potential impact on system availability and responsiveness

Technical summary

The shell-quote package prior to version 1.8.5 has a vulnerability that can cause a denial of service (DoS) attack. The parse() function uses Array.prototype.concat as a reduce accumulator, resulting in O(n^2) time complexity. This can be exploited by an attacker who can supply a specially crafted string to any code path that calls parse(). The vulnerability impacts system availability and responsiveness, with high CPU usage and potential system slowdown. Developers and administrators should assess their exposure and take necessary actions to mitigate the vulnerability.

Defensive priority

High priority for systems using the shell-quote package, especially those with high availability requirements.

Recommended defensive actions

• Update the shell-quote package to version 1.8.5 or later
• Review and monitor code paths that use the parse() function
• Implement input validation and sanitization for user-supplied strings
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance.
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.

Evidence notes

The vulnerability is confirmed by the CVE Program and NVD. The shell-quote project has released a fix in version 1.8.5. Evidence limits are based on CVE and NVD records. Affected scope and impact are limited to denial of service (DoS) attacks. Defenders should verify system exposure, review code paths using the parse() function, and implement input validation.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.