CVE-2026-9277

8.1 HIGH
Published: May 22, 2026 Modified: May 23, 2026
View on NVD

Description

shell-quote's `quote()` function did not validate object-token inputs against the operator model used by `parse()`. The `.op` field was backslash-escaped character by character using `/(.)/g`, which in JavaScript does not match line terminators (\n, \r, U+2028, U+2029). A line terminator in `.op` therefore passed through unescaped into the output; POSIX shells treat a literal newline as a command separator, so any content after it would execute as a second command. The vulnerable code path is reachable in two ways: (1) direct construction of `{ op: '...\n...' }` from external input, and (2) via `parse(cmd, envFn)` when `envFn` returns object tokens whose `.op` is attacker-influenced. Both are documented API surface. Fixed by replacing the per-character escape with strict shape validation: `.op` must match the parser's control-operator allowlist; `{ op: 'glob', pattern }` validates `pattern` and forbids line terminators; `{ comment }` validates `comment` and forbids line terminators; any other object shape throws `TypeError`.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://github.com/ljharb/shell-quote
Source: 7ffcee3d-2c14-4c3e-b844-86c6a321a158
https://github.com/ljharb/shell-quote/commit/1518179
Source: 7ffcee3d-2c14-4c3e-b844-86c6a321a158
https://www.npmjs.com/package/shell-quote
Source: 7ffcee3d-2c14-4c3e-b844-86c6a321a158
http://www.openwall.com/lists/oss-security/2026/05/23/2
Source: af854a3a-2127-422b-91ae-364da2661108

6 reference(s) from NVD

Quick Stats

CVSS v3 Score
8.1 / 10.0
EPSS (Exploit Probability)
0.6%
42th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)