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🛡️ CVE-2025-50181 — urllib3

🟡 CVSS 5.3 — Medium ⚠️ Exploit Public CWE-601 OSV
5.3
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

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 [[email protected]](mailto:[email protected]) to discuss sponsorship or contribution opportunities.
  • Disable redirects at the request() level instead of the PoolManager() level.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is high, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity none, availability none.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N

  • Attack vector: Network — reachable from anywhere that can route to the service.
  • Attack complexity: High — the attacker first has to win a race, learn a secret or otherwise prepare the target.
  • Privileges required: Low — an ordinary user account is enough.
  • User interaction: None — nobody has to be tricked into anything.
  • Scope: Unchanged — the damage stays inside the vulnerable component.
  • Confidentiality impact: High — total loss, or loss the attacker controls.
  • Integrity impact: None.
  • Availability impact: None.

Weakness class

CVE-2025-50181 is classified as CWE-601: Open Redirect. A redirect target is taken from user input, so a trusted link can send the visitor to an attacker's site.

Affected software

CVE-2025-50181 is recorded against 1 package.

  • urllib3 (fixed in 2.5.0)

Timeline and source

Published on 18 June 2025 and last revised on 7 July 2026. A public exploit is known to exist, which raises the urgency of patching considerably. A vendor advisory or fix has been published. Record sourced from OSV.

References

github.com (Web)
nvd.nist.gov (Advisory)
github.com (Web)
github.com (Package)
github.com (Web)

Other advisories for this package

urllib3 has other advisories on record. If you are patching this one, these are worth checking on the same host:

Same weakness in other software

These advisories are the same class of weakness (CWE-601: Open Redirect) in other software:

CVE-2025-50181 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity MEDIUM
CVSS Score 5.3
CVSS Vector CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
CWE CWE-601
Public Exploit ⚠️ Yes
Source OSV
Published 2025-06-18
Updated 2026-08-20
Modified 2026-07-07

Affected Packages

Software From version Fixed in
urllib3 — 2.5.0

Exploit Protection

Are you running urllib3?

CVE-2025-50181 carries CVSS 5.3 Medium rating and a public exploit already exists. BotEraser checks your installation against this and other known CVE records, and blocks IPs associated with exploit activity.

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