CVE Catalog

CVE-2026-9277

HighCVSS 8.1
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Elevated risk
0.85%

56th percentile - higher than 56% of all known CVEs

Summary

In shell-quote, the 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 fix replaces per-character escape with strict shape validation.

Risk Assessment

An attacker can inject arbitrary shell commands, potentially leading to remote code execution on the server.

Recommendation

Upgrade shell-quote to a version containing the fix.

Related vulnerabilities

Original NVD description (English source)

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`.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS