CVE-2025-50181 – urllib3

Package

Manager: pip
Name: urllib3
Vulnerable Version: >=0 <2.5.0

Severity

Level: Medium

CVSS v3.1: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N

CVSS v4.0: CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

EPSS: 0.00015 pctl0.02007

Details

urllib3 redirects are not disabled when retries are disabled on PoolManager instantiation urllib3 handles redirects and retries using the same mechanism, which is controlled by the `Retry` object. The most common way to disable redirects is at the request level, as follows: ```python resp = urllib3.request("GET", "https://httpbin.org/redirect/1", redirect=False) print(resp.status) # 302 ``` However, it is also possible to disable redirects, for all requests, by instantiating a `PoolManager` and specifying `retries` in a way that disable redirects: ```python import urllib3 http = urllib3.PoolManager(retries=0) # should raise MaxRetryError on redirect http = urllib3.PoolManager(retries=urllib3.Retry(redirect=0)) # equivalent to the above http = urllib3.PoolManager(retries=False) # should return the first response resp = http.request("GET", "https://httpbin.org/redirect/1") ``` However, the `retries` parameter is currently ignored, which means all the above examples don't disable redirects. ## Affected usages Passing `retries` on `PoolManager` instantiation to disable redirects or restrict their number. By default, requests and botocore users are not affected. ## Impact Redirects are often used to exploit SSRF vulnerabilities. An application attempting to mitigate SSRF or open redirect vulnerabilities by disabling redirects at the PoolManager level will remain vulnerable. ## Remediation You can remediate this vulnerability with the following steps: * Upgrade to a patched version of urllib3. If your organization would benefit from the continued support of urllib3 1.x, please contact [sethmichaellarson@gmail.com](mailto:sethmichaellarson@gmail.com) to discuss sponsorship or contribution opportunities. * Disable redirects at the `request()` level instead of the `PoolManager()` level.

Metadata

Created: 2025-06-18T17:50:00Z
Modified: 2025-06-19T15:18:59Z
Source: https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/06/GHSA-pq67-6m6q-mj2v/GHSA-pq67-6m6q-mj2v.json
CWE IDs: ["CWE-601"]
Alternative ID: GHSA-pq67-6m6q-mj2v
Finding: F156
Auto approve: 1