pyLoad: Unprotected storage_folder enables arbitrary file write to Flask session store and code execution (Incomplete fix for CVE-2026-33509)

Exploitation

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

CVSS

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

EPSS

• CVE-2026-35464: 0.53% estimated exploitation activity in the next 30 days; percentile 44.80 (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 (GHSA-r7mc-x6x7-cqxx) added an ADMINONLYOPTIONS set to block non-admin users from modifying security-critical config options. The storagefolder option is not in this set and passes the existing path restriction because the Flask session directory is outside both PKGDIR and userdir. A user with SETTINGS and ADD permissions can redirect downloads to the Flask filesystem session store, plant a malicious pickle payload as a predictable session file, and trigger arbitrary code execution when any HTTP request arrives with the corresponding session cookie. Required Privileges The chain requires a single non-admin user with both SETTINGS (to change storagefolder) and ADD (to submit a download URL) permissions. These are independent bitmask flags that can be assigned together by an admin. The final RCE trigger is unauthenticated: any HTTP request with the crafted session cookie causes deserialization. Root Cause storagefolder at…

Published by the source

4 Apr 2026, 06:43 UTC

Last modified by the source

10 Sep 2026, 03:50 UTC

Source last checked

26 Oct 2026, 13:40 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-4744-96p5-mp2j

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-4744-96p5-mp2j

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# Patch Next advisory brief: CVE-2026-35464

Advisory: pyLoad: Unprotected storage_folder enables arbitrary file write to Flask session store and code execution (Incomplete fix for CVE-2026-33509)
IDs: CVE-2026-35464, GHSA-4744-96p5-mp2j
Record: https://patchnext.com/advisories/cve-2026-35464 (revision 2, source checked 26 Oct 2026, 13:40 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
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

## 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-4744-96p5-mp2j (OSV record GHSA-4744-96p5-mp2j lists affected ranges: PyPI pyload-ng >=0 <=0.5.0b3)
- Verified: https://github.com/advisories/GHSA-4744-96p5-mp2j (GitHub-reviewed advisory GHSA-4744-96p5-mp2j lists affected ranges: PyPI pyload-ng >=0 <=0.5.0b3)

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