vulnerability / NVI-00016295 / Revision 2
shell-quote: Quadratic-complexity Denial of Service in `parse()` (CWE-407)
GitHub lists this reviewed advisory for shell-quote. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
7.5 high
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
7.5 HIGH (3.1)
7ffcee3d-2c14-4c3e-b844-86c6a321a158 severity; no combined Null risk score.
8.7 HIGH (4.0)
7ffcee3d-2c14-4c3e-b844-86c6a321a158 severity; no combined Null risk score.
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
shell-quote
source listed<= 1.8.4
### Summary `shell-quote`'s `parse()` finalizes its token list with a `reduce` that uses `Array.prototype.concat` as the accumulator. Each `prev.concat(arg)` copies the entire growing array, so `parse()` runs in **O(n²)** in the number of tokens. An unauthenticated attacker who can submit a string to any code path that calls `parse()` on it can block the single-threaded Node.js event loop for tens of seconds with a small input — a denial of service. The trigger needs **no shell metacharacters** (plain space-separated words suffice), so input filters that only screen for `;`, `|`, `$`, or backticks do not help. ### Root cause `parse.js` (lines 200–203), in `parseInternal` — this path runs on **every** `parse()` call: ```js }).reduce(function (prev, arg) { // finalize parsed arguments // TODO: replace this whole reduce with a concat return typeof arg === 'undefined' ? prev : prev.concat(arg); }, []); ``` `prev.concat(arg)` allocates a new array and copies all of `prev` on every iteration, so producing an N-token result costs `1 + 2 + … + N = O(N²)` copies. A second `acc.concat(s)` reduce in the `module.exports` wrapper (lines 211–224, reached only when `env` is a function)
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. NIST National Vulnerability Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
- NVD lastModified does not establish freshness of every associated CPE record.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-395f-4hp3-45gv ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
- CVE-2026-13311 ↗
NIST National Vulnerability Database · official catalog
Observed . This product uses data from the NVD API but is not endorsed or certified by the NVD.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 2 ·
Source facts changed; compare the preserved prior revision.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.