Insertion of Sensitive Information Into Sent Data Affecting urllib3 package, versions [1.23,2.7.0)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-PYTHON-URLLIB3-16642024
- published12 May 2026
- disclosed11 May 2026
- creditchristos-spearbit
Introduced: 11 May 2026
CVE-2026-44431 (opens in a new tab)How to fix?
Upgrade urllib3 to version 2.7.0 or higher.
Overview
urllib3 is a HTTP library with thread-safe connection pooling, file post, and more.
Affected versions of this package are vulnerable to Insertion of Sensitive Information Into Sent Data in urlopen() when using ProxyManager.connection_from_url() with assert_same_host=False, directly rather than via the high-level APIs including urllib3.request(), PoolManager.request(), and ProxyManager.request(). An attacker can expose headers such as Authorization, Cookie, and Proxy-Authorization by triggering cross-origin redirects, which does not properly invoke remove_headers_on_redirect.