CVE-2026-35464 is a high-severity (CVSS 7.5) Deserialization of Untrusted Data vulnerability in pyload-ng. No vendor fix is recorded yet; mitigation options are listed below.
pyLoad has an incomplete fix for CVE-2026-33509: unprotected storage_folder enables arbitrary file write to Flask session store and code execution
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-35464.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2026-35464 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,333 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
pyload-ngReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | pyload-ng | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pyload-ng, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
No patched version of pyload-ng has shipped for CVE-2026-35464 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-35464 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-35464. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-35464 in your dependencies?
O3 Security finds CVE-2026-35464 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.