@tinacms/graphql's FilesystemBridge Path Validation Can Be Bypassed via Symlinks or Junctions

Exploitation

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

CVSS

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

EPSS

• CVE-2026-34604: 0.38% estimated exploitation activity in the next 30 days; percentile 31.89 (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 @tinacms/graphql uses string-based path containment checks in FilesystemBridge: - path.resolve(path.join(baseDir, filepath)) - startsWith(resolvedBase + path.sep) That blocks plain ../ traversal, but it does not resolve symlink or junction targets. If a symlink/junction already exists under the allowed content root, a path like content/posts/pivot/owned.md is still considered "inside" the base even though the real filesystem target can be outside it. As a result, FilesystemBridge.get(), put(), delete(), and glob() can operate on files outside the intended root. Details The current bridge validation is: But the bridge then performs real filesystem I/O on the resulting path: This is a classic realpath gap: 1. validation checks the lexical path string 2. the filesystem follows the link target during I/O 3. the actual target can be outside the intended root This is reachable from Tina's GraphQL/local database flow. The resolver builds a validated path from user-controlled…

Published by the source

1 Apr 2026, 00:25 UTC

Last modified by the source

6 Apr 2026, 17:04 UTC

Source last checked

26 Oct 2026, 12:47 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-g9c2-gf25-3x67

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-g9c2-gf25-3x67

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# Patch Next advisory brief: CVE-2026-34604

Advisory: @tinacms/graphql's `FilesystemBridge` Path Validation Can Be Bypassed via Symlinks or Junctions
IDs: CVE-2026-34604, GHSA-g9c2-gf25-3x67
Record: https://patchnext.com/advisories/cve-2026-34604 (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: High (CVSS 7.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: @tinacms/graphql 2.2.2. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm @tinacms/graphql: affected <= 2.2.0; fixed in 2.2.2

## Suggested inspection (read-only)
- `npm ls @tinacms/graphql --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 @tinacms/graphql.
- 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-g9c2-gf25-3x67 (OSV record GHSA-g9c2-gf25-3x67 lists affected ranges: npm @tinacms/graphql >=0 <2.2.2 (fixed))
- Verified: https://github.com/advisories/GHSA-g9c2-gf25-3x67 (GitHub-reviewed advisory GHSA-g9c2-gf25-3x67 lists affected ranges: npm @tinacms/graphql >=0 <=2.2.0)

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