# CVE-2026-35464: pyLoad: Unprotected storage_folder enables arbitrary file write to Flask session store and code execution (Incomplete fix for CVE-2026-33509)

> A user with settings permissions can redirect downloads to the session store to plant a malicious pickle payload, leading to arbitrary code execution.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 7 Apr 2026
- **Updated:** 7 Apr 2026
- **Also known as:** GHSA-4744-96p5-mp2j, PYSEC-2026-2989

## What is CVE-2026-35464?

CVE-2026-35464 is a high-severity unsafe deserialization vulnerability in pyload, published on 7 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

pyLoad is a free and open-source download manager written in Python. The fix for CVE-2026-33509 added an ADMIN_ONLY_OPTIONS set to block non-admin users from modifying security-critical config options. The storage_folder 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. This vulnerability is fixed with commit c4cf995a2803bdbe388addfc2b0f323277efc0e1.

Weakness: CWE-863 (Incorrect Authorization), CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2026-35464?

3 open source packages ship an affected version, including pyload-ng. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `pyload-ng` | PyPI | All versions to 0.5.0b3 | None |
| `pyload-ng` | PyPI | All versions to 0.5.0b3 | None |
| `pyload-ng` | PyPI | All versions to 0.5.0b3 | None |

Products: Pyload Pyload.

## How do I fix CVE-2026-35464?

No fix has been published for CVE-2026-35464 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-35464 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-35464 exists.

## Other vulnerabilities in pyload

- [CVE-2023-0297](https://insights.sbomify.com/CVE-2023-0297/): Code Injection in pyload/pyload (critical 9.8)
- [CVE-2026-33992](https://insights.sbomify.com/CVE-2026-33992/): pyLoad: Server-Side Request Forgery via Download Link Submission Enables Cloud Metadata Exfiltration (critical 9.3)
- [CVE-2024-47821](https://insights.sbomify.com/CVE-2024-47821/): pyLoad vulnerable to remote code execution by download to /.pyload/scripts using /flashgot API (critical 9.1)
- [CVE-2024-32880](https://insights.sbomify.com/CVE-2024-32880/): pyLoad allows upload to arbitrary folder lead to RCE (critical 9.1)
- [CVE-2026-41133](https://insights.sbomify.com/CVE-2026-41133/): pyLoad has Stale Session Privilege After Role/Permission Change (Privilege Revocation Bypass) (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-35464 and fix it if it is affected.

What it is: CVE-2026-35464 is a high-severity unsafe deserialization vulnerability in pyload, published on 7 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-35464 exists.

Affected packages and fixed versions:
- pyload-ng (PyPI): affected all versions up to 0.5.0b3; no fix listed
- pyload-ng (PyPI): affected all versions up to 0.5.0b3; no fix listed
- pyload-ng (PyPI): affected all versions up to 0.5.0b3; no fix listed

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-35464/ (Markdown: https://insights.sbomify.com/CVE-2026-35464/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-35464
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-35464
- OSV: https://osv.dev/vulnerability/CVE-2026-35464

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-35464/
Summaries are generated and may contain mistakes; the official description above is the record.