OnionShare Receive mode writes uploaded files even when file uploads are disabled

Exploitation

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

CVSS

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

EPSS

• CVE-2026-54707: 0.40% estimated exploitation activity in the next 30 days; percentile 34.27 (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 OnionShare CLI/Desktop 2.6.3 does not enforce the Receive mode disablefiles setting at the file upload sink. When a Receive service is configured as a text-message-only endpoint (--disable-files / "Disable uploading files"), a remote sender who can reach the OnionShare service can still send a crafted multipart request containing file[]; OnionShare writes the uploaded bytes to disk before the route handler skips file accounting. This affects the shipped onionshare-cli Python package and the desktop application because both use the same onionsharecli.web.receivemode request-streaming implementation. Details Tested repository: https://github.com/onionshare/onionshare at commit 8cc75e1d7e88bd31f7276733449d412bf71c8999. Affected product evidence: - cli/pyproject.toml declares onionsharecli version 2.6.3. - desktop/pyproject.toml declares onionshare version 2.6.3 and depends on onionsharecli from ../cli. - cli/setup.py publishes onionshare-cli and includes onionsharecli.web plus…

Published by the source

31 Jul 2026, 16:27 UTC

Last modified by the source

31 Jul 2026, 16:28 UTC

Source last checked

26 Oct 2026, 13:50 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-v833-3823-cmhp

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-54707

Advisory: OnionShare Receive mode writes uploaded files even when file uploads are disabled
IDs: CVE-2026-54707, GHSA-v833-3823-cmhp
Record: https://patchnext.com/advisories/cve-2026-54707 (revision 1, source checked 26 Oct 2026, 13:50 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.4)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: onionshare-cli 2.6.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI onionshare-cli: affected < 2.6.4; fixed in 2.6.4

## Suggested inspection (read-only)
- `python -m pip show onionshare-cli`: 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 onionshare-cli.
- 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-v833-3823-cmhp (GitHub-reviewed advisory GHSA-v833-3823-cmhp lists affected ranges: PyPI onionshare-cli >=0 <2.6.4)

Commands are suggestions: review each one before running it.