SillyTavern: Path Traversal allows file existence oracle

Exploitation

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

CVSS

5.3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

EPSS

• CVE-2026-34523: 0.47% estimated exploitation activity in the next 30 days; percentile 40.47 (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.

Summary A path traversal vulnerability in the static file route handler allows any unauthenticated user to determine whether files exist anywhere on the server's filesystem. By sending percent-encoded ../ sequences (%2E%2E%2F) in requests to static file routes, an attacker can check for the existence of files (404 if it doesn't exist, 403 means it exists). Details The vulnerability is in createRouteHandler (src/users.js:947–963), which backs all user-data static file routes: req.params[0] contains the raw (percent-encoded) wildcard from the URL. After decodeURIComponent, a request path like /characters/%2E%2E%2F%2E%2E%2FUsers/kirakira decodes to ../../Users/kirakira, and path.join resolves it outside the intended directory. res.sendFile correctly blocks the file from being served (the send module's root check returns 403), but fs.existsSync had already run, and the 403/404 distinction reveals the result. Affected routes (they all use the same handler, so they're all affected): -…

Published by the source

1 Apr 2026, 21:40 UTC

Last modified by the source

6 Apr 2026, 17:31 UTC

Source last checked

26 Oct 2026, 12:47 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-525j-2hrj-m8fp

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-525j-2hrj-m8fp

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# Patch Next advisory brief: CVE-2026-34523

Advisory: SillyTavern: Path Traversal allows file existence oracle
IDs: CVE-2026-34523, GHSA-525j-2hrj-m8fp
Record: https://patchnext.com/advisories/cve-2026-34523 (revision 2, source checked 26 Oct 2026, 12:47 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: sillytavern 1.17.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm sillytavern: affected <= 1.16.0; fixed in 1.17.0

## Suggested inspection (read-only)
- `npm ls sillytavern --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## 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 sillytavern.
- 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://osv.dev/vulnerability/GHSA-525j-2hrj-m8fp (OSV record GHSA-525j-2hrj-m8fp lists affected ranges: npm sillytavern >=0 <1.17.0 (fixed))
- Verified: https://github.com/advisories/GHSA-525j-2hrj-m8fp (GitHub-reviewed advisory GHSA-525j-2hrj-m8fp lists affected ranges: npm sillytavern >=0 <=1.16.0)

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