Vulnerability in Ljharb Shell-Quote
CVE-2026-13311
shell-quote prior to 1.8.5 finalizes parsed tokens in parse() using Array.prototype.concat as a reduce accumulator, which reallocates and copies the entire growing array on every iteration. As a result parse() runs in O(n^2) time relative to the number of input tokens. An attacker who can supply an attacker-controlled string to any code path that calls parse() (no shell metacharacters are required; plain space-separated words suffice) can block the single-threaded Node.js event loop for an extended period with a small input, resulting in a denial of service. There is no code execution or data disclosure; impact is to availability only. Fixed in 1.8.5.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.006 (46.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 46th percentile — 46.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.006 · change: +0.002
Affected products
- Ljharb Shell-Quote — versions 0
- Shell-Quote Project
Weakness classification (CWE)
References
- 7ffcee3d-2c14-4c3e-b844-86c6a321a158 (vendor-advisory, Vendor Advisory)
- 7ffcee3d-2c14-4c3e-b844-86c6a321a158 (Product, product)
Frequently asked questions
- What is CVE-2026-13311?
- CVE-2026-13311 is a high-severity vulnerability in Ljharb Shell-Quote, classified under Inefficient Algorithmic Complexity. CVSS score: 7.5/10. Published 2026-06-25.
- How severe is CVE-2026-13311?
- High severity. CVSS v3 base score is 7.5 out of 10.