Saltcorn has an Unauthenticated Path Traversal in sync endpoints, allowing arbitrary file write and directory read

Exploitation

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

CVSS

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

EPSS

• CVE-2026-40163: 0.33% estimated exploitation activity in the next 30 days; percentile 26.74 (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 Two unauthenticated path traversal vulnerabilities exist in Saltcorn's mobile sync endpoints. The POST /sync/offlinechanges endpoint allows an unauthenticated attacker to create arbitrary directories and write a changes.json file with attacker-controlled JSON content anywhere on the server filesystem. The GET /sync/uploadfinished endpoint allows an unauthenticated attacker to list arbitrary directory contents and read specific JSON files. The safe path validation function File.normaliseinbase() exists in the codebase and is correctly used by the cleansyncdir endpoint in the same file (fix for GHSA-43f3-h63w-p6f6), but was not applied to these two endpoints. Details Finding 1: Arbitrary file write — POST /sync/offlinechanges (sync.js line 226) The newSyncTimestamp parameter from the request body is used directly in path.join() without sanitization: No authentication middleware is applied to this route. Since path.join() normalizes ../ sequences, setting newSyncTimestamp to…

Published by the source

10 Apr 2026, 19:30 UTC

Last modified by the source

10 Apr 2026, 19:56 UTC

Source last checked

26 Oct 2026, 12:48 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-32pv-mpqg-h292

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-32pv-mpqg-h292

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# Patch Next advisory brief: CVE-2026-40163

Advisory: Saltcorn has an Unauthenticated Path Traversal in sync endpoints, allowing arbitrary file write and directory read
IDs: CVE-2026-40163, GHSA-32pv-mpqg-h292
Record: https://patchnext.com/advisories/cve-2026-40163 (revision 2, source checked 26 Oct 2026, 12:48 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.2)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: @saltcorn/server 1.6.0-beta.4, 1.5.5, 1.4.5. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm @saltcorn/server: affected < 1.4.5; >= 1.5.0-beta.0, < 1.5.5; >= 1.6.0-alpha.0, < 1.6.0-beta.4; fixed in 1.4.5, 1.6.0-beta.4, 1.5.5

## Suggested inspection (read-only)
- `npm ls @saltcorn/server --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 @saltcorn/server.
- 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-32pv-mpqg-h292 (OSV record GHSA-32pv-mpqg-h292 lists affected ranges: npm @saltcorn/server >=0 =1.5.0-beta.0 =1.6.0-alpha.0 <1.6.0-beta.4 (fixed))
- Verified: https://github.com/advisories/GHSA-32pv-mpqg-h292 (GitHub-reviewed advisory GHSA-32pv-mpqg-h292 lists affected ranges: npm @saltcorn/server >=0 =1.5.0-beta.0 =1.6.0-alpha.0 <1.6.0-beta.4)

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