CVE-2026-102422

shell-quote `quote()` command injection via a line terminator in a token after a `{ comment }` token

Published Sep 29, 2026 CVSS 4.0 · 9.2 Critical EPSS < 1% KEV · Not listed
Description
shell-quote's `quote()` function emits a `{ comment }` token as `#` followed by its text, which comments out the rest of the shell line, including the opening quote of any later string token. A line terminator (\n, \r, U+2028, U+2029) in that later string therefore ends the comment, and the rest of the string is parsed as shell input: `quote(['echo', 'ok', { comment: 'x' }, 'a\nid;#'])` runs `id` in sh, bash, dash, ksh and zsh. `parse()` emits a comment token for a `#` in the middle of a word (for example `http://example.com/#frag`), so callers that combine `parse()` output with another untrusted string, such as `quote(parse(untrustedCommand).concat(untrustedArg))`, are affected. The fix for CVE-2026-9277 rejected line terminators in the comment's own text, but not in the tokens after it. Fixed in 1.11.0: `quote()` throws a `TypeError` when a string after a `{ comment }` token contains a line terminator.

Analysis

AI-generated

Technical impact

The shell-quote library’s quote() function generates a comment token (#) that comments out the remainder of the shell line. If a line terminator (\n, \r, U+2028, U+2029) appears in a subsequent string token, the comment ends at that point, causing the remainder of the string to be parsed as active shell input. Malicious callers that supply untrusted data to quote() or combine parse() output with untrusted arguments can therefore inject arbitrary shell commands such as id, resulting in full command execution in the context of the running process. This vulnerability is a classic command injection flaw, represented by CWE‑78.

Affected Systems

This issue affects the npm package shell-quote for all Node.js applications that use the quote() or parse() functions to construct shell commands. Versions prior to 1.11.0 are vulnerable; version 1.11.0 and later contain a guard that throws a TypeError when a string following a { comment } token contains a line terminator.

Risk and Exploitability

The vulnerability carries a CVSS score of 9.2, indicating high severity. The EPSS score is not available, and it is not listed in CISA’s KEV catalog, suggesting no widespread exploitation reports yet. Nevertheless, the flaw is exploitable in any context where untrusted user input is passed to quote() or parse() and concatenated with other command components, without additional validation. Attackers could exploit this remotely if the application accepts user-controlled input that eventually flows to shell-quote; no privileged access is required beyond the execution context of the vulnerable process.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Upgrade shell-quote to version 1.11.0 or later, which rejects injected line terminators in strings following comment tokens.
  • Validate or sanitize any untrusted strings before passing them to quote() or parse(), removing line terminators, comment tokens, and other shell meta-characters.
  • Refactor code to avoid concatenating parse() output with untrusted data; use safer APIs or libraries that escape all shell arguments automatically.

Generated by OpenCVE AI on September 29, 2026 at 05:21 UTC.

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4901-1 node-shell-quote security update
Debian DSA Debian DSA DSA-6548-1 node-shell-quote security update
Github GHSA Github GHSA GHSA-pqg4-j6r4-53mv shell-quote: `quote()` command injection via a line terminator in a token after a `{ comment }` token
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Ljharb
Ljharb shell-quote
Vendors & Products Ljharb
Ljharb shell-quote
Type Values Removed Values Added
Description shell-quote's `quote()` function emits a `{ comment }` token as `#` followed by its text, which comments out the rest of the shell line, including the opening quote of any later string token. A line terminator (\n, \r, U+2028, U+2029) in that later string therefore ends the comment, and the rest of the string is parsed as shell input: `quote(['echo', 'ok', { comment: 'x' }, 'a\nid;#'])` runs `id` in sh, bash, dash, ksh and zsh. `parse()` emits a comment token for a `#` in the middle of a word (for example `http://example.com/#frag`), so callers that combine `parse()` output with another untrusted string, such as `quote(parse(untrustedCommand).concat(untrustedArg))`, are affected. The fix for CVE-2026-9277 rejected line terminators in the comment's own text, but not in the tokens after it. Fixed in 1.11.0: `quote()` throws a `TypeError` when a string after a `{ comment }` token contains a line terminator.
Title shell-quote `quote()` command injection via a line terminator in a token after a `{ comment }` token
Weaknesses CWE-78
References
Metrics cvssV3_1

{'score': 8.1, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 9.2, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}

Weaknesses
  • CWE-78

    Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

Sources

Status
PUBLISHED
Assigner
harborist
Published
Updated
Sep 30, 2026, 3:18 PM
Reserved
Sep 29, 2026, 3:43 AM
Status
Deferred
Published
Sep 29, 2026, 4:17 AM
Modified
Sep 30, 2026, 5:32 PM
Severity
Important
Public date
Sep 29, 2026, 3:47 AM