Shiny for Python has path traversal in bookmark restore

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

6.9 · 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 · score source

EPSS

• CVE-2026-108258: 0.36% estimated exploitation activity in the next 30 days; percentile 29.59 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact Shiny for Python's bookmark-restore path accepted a client-supplied stateid query-string value and joined it into the server-side bookmark directory (<cwd/shinybookmarks/<id) without validating it. A value containing .. path segments, or an absolute path, could therefore cause the server to open and parse input.json and values.json from a directory outside the bookmark store. On a default application the restore was attempted whenever the client supplied a URL query string — including when bookmarking was disabled (bookmarkstore="disable") — so no opt-in configuration was required. For such applications the impact is an unauthenticated, server-side probe for the existence and JSON-validity of attacker-chosen paths, constrained to those two file names. Applications configured with bookmarkstore="server" and using ui.inputfile() are affected more seriously. The file-input restore handler copies files out of the restore directory, so the contents of an attacker-selected file name…

Published by the source

9 Oct 2026, 20:56 UTC

Last modified by the source

15 Oct 2026, 14:56 UTC

Source last checked

26 Oct 2026, 13:55 UTC

1. Revision 4 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-47c3-hpmg-7j6p

2. Revision 3 · amended · 25 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GHSA-47c3-hpmg-7j6p

4. Revision 1 · created · 23 Oct 2026

   Published from ghsa record GHSA-47c3-hpmg-7j6p

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# Patch Next advisory brief: CVE-2026-108258

Advisory: Shiny for Python has path traversal in bookmark restore
IDs: CVE-2026-108258, GHSA-47c3-hpmg-7j6p
Record: https://patchnext.com/advisories/cve-2026-108258 (revision 4, source checked 26 Oct 2026, 13:55 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: shiny 1.6.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI shiny: affected >= 1.4.0, <= 1.6.3; fixed in 1.6.4

## Suggested inspection (read-only)
- `python -m pip show shiny`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on shiny.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-47c3-hpmg-7j6p (GitHub-reviewed advisory GHSA-47c3-hpmg-7j6p lists affected ranges: PyPI shiny >=1.4.0 <=1.6.3)
- Verified: https://osv.dev/vulnerability/GHSA-47c3-hpmg-7j6p (OSV record GHSA-47c3-hpmg-7j6p lists affected ranges: PyPI shiny >=1.4.0 <1.6.4 (fixed))

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