CVE-2026-102422: shell-quote `quote()` command injection via a line terminator in a token after a `{ comment }` token

Severity: high (CVSS 8.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-29 · updated 2026-09-30
Weakness: CWE-78

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.

Affected products

Shell-Quote: from 1.8.4 before 1.11.0 — fixed in 1.11.0

How to fix

Upgrade to a fixed version: Shell-Quote 1.11.0. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2026-102422 or the next vulnerability affects your stack