{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 1.6.3"
      },
      "package": {
        "ecosystem": "PyPI",
        "name": "shiny"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.4.0"
            },
            {
              "fixed": "1.6.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-108258"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-22"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-10-09T20:56:37Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "### Impact\n\nShiny for Python\u0027s bookmark-restore path accepted a client-supplied `_state_id_`\nquery-string value and joined it into the server-side bookmark directory\n(`\u003ccwd\u003e/shiny_bookmarks/\u003cid\u003e`) without validating it. A value containing `..`\npath segments, or an absolute path, could therefore cause the server to open and\nparse `input.json` and `values.json` from a directory outside the bookmark store.\n\nOn a default application the restore was attempted whenever the client supplied a\nURL query string \u2014 including when bookmarking was disabled\n(`bookmark_store=\"disable\"`) \u2014 so no opt-in configuration was required. For such\napplications the impact is an unauthenticated, server-side probe for the\nexistence and JSON-validity of attacker-chosen paths, constrained to those two\nfile names.\n\nApplications configured with `bookmark_store=\"server\"` **and** using\n`ui.input_file()` are affected more seriously. The file-input restore handler\ncopies files out of the restore directory, so the contents of an\nattacker-selected file name within an attacker-selected directory could be read\ninto the application.\n\n### Affected versions\n\n1.4.0 through 1.6.3. Bookmarking was introduced in 1.4.0; earlier releases do\nnot contain the affected code path and are not affected.\n\n### Patches\n\nFixed in **1.6.4**. Upgrade with:\n\n```\npip install --upgrade shiny\n```\n\nThe fix validates bookmark IDs against an allowlist \u2014 a single path segment\nmatching `[A-Za-z0-9_-]+`, which cannot express a path separator, a `..` parent\nreference, or an absolute path \u2014 before the ID is used to build a filesystem\npath. Bookmark IDs generated by Shiny are unaffected by this restriction.\nRestore is additionally gated on the application\u0027s `bookmark_store` setting at a\nsingle point, so it no longer runs when bookmarking is disabled, and the on-disk\nrestore path is honored only under `bookmark_store=\"server\"`.\n\n### Workarounds\n\nThere is no configuration change that mitigates this on an affected version:\nthe restore path ran even with `bookmark_store=\"disable\"`. Deployments that\ncannot upgrade immediately can strip the `_state_id_` parameter from incoming\nquery strings at a reverse proxy or load balancer, which prevents the affected\ncode path from being reached.\n\n### Credits\n\nReported by [@0xRenSec](https://github.com/0xRenSec).",
  "id": "GHSA-47c3-hpmg-7j6p",
  "modified": "2026-10-09T20:56:37Z",
  "published": "2026-10-09T20:56:37Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/posit-dev/py-shiny/security/advisories/GHSA-47c3-hpmg-7j6p"
    },
    {
      "type": "WEB",
      "url": "https://github.com/posit-dev/py-shiny/commit/1d8ecb46cbc9621b7dc8812111d26692e086b376"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/posit-dev/py-shiny"
    },
    {
      "type": "WEB",
      "url": "https://github.com/posit-dev/py-shiny/releases/tag/v1.6.4"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Shiny for Python has path traversal in bookmark restore"
}