pyLoad Has Incomplete Fix for CVE-2026-33509 -storage_folder Bypass via Session Directory in pyLoad

Exploitation

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

CVSS

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

EPSS

• CVE-2026-45306: 0.23% estimated exploitation activity in the next 30 days; percentile 14.43 (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 The fix for CVE-2026-33509 prevents setting storagefolder inside PKGDIR or userdir, but does NOT protect the Flask session directory (/tmp/pyLoad/flask). An authenticated attacker can set storagefolder to the session directory and download session files of other users via /files/get/, leading to account takeover. Details The fix in src/pyload/core/api/init.py: But the Flask session directory is: Attack Chain 1. Attacker (admin) sets storagefolder = /tmp/pyLoad/flask 2. Fix does NOT block this — /tmp/pyLoad/flask not inside PKGDIR or userdir 3. Attacker requests GET /files/get/<victimsessionfilename 4. sendfromdirectory('/tmp/pyLoad/flask', sessionfile) serves victim's session 5. Attacker uses stolen session → Account Takeover PoC <img width="592" height="408" alt="POC" src="https://github.com/user-attachments/assets/936b9f56-325b-437d-9edd-e0d5bb995187" / Impact Authenticated admin can steal sessions of other users → Account Takeover. Suggested Fix

Published by the source

14 May 2026, 20:17 UTC

Last modified by the source

13 Jul 2026, 16:43 UTC

Source last checked

26 Oct 2026, 13:45 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-w727-595x-pc3r

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-w727-595x-pc3r

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# Patch Next advisory brief: CVE-2026-45306

Advisory: pyLoad Has Incomplete Fix for CVE-2026-33509 -storage_folder Bypass via Session Directory in pyLoad
IDs: CVE-2026-45306, GHSA-w727-595x-pc3r
Record: https://patchnext.com/advisories/cve-2026-45306 (revision 2, source checked 26 Oct 2026, 13:45 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI pyload-ng: affected <= 0.5.0b3.dev99

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

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on pyload-ng.
- 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-w727-595x-pc3r (OSV record GHSA-w727-595x-pc3r lists affected ranges: PyPI pyload-ng >=0 <=0.5.0b3.dev99)
- Verified: https://github.com/advisories/GHSA-w727-595x-pc3r (GitHub-reviewed advisory GHSA-w727-595x-pc3r lists affected ranges: PyPI pyload-ng >=0 <=0.5.0b3.dev99)

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