Urllib3 vulnerabilities
We track 7 vulnerabilities in Urllib3 products. 7 are rated high or critical, and none are known to be exploited. The most recent was published on September 29, 2026.
Latest Urllib3 vulnerabilities
- 7.5 High severity
urllib3: Allocation of Resources Without Limits or Throttling
urllib3 is an HTTP client library for Python. From 1.10.3 until 2.8.0, the HTTPResponse.read_chunked and HTTPResponse.stream methods can allocate unbounded memory because the streaming chunk parser buffers the chunk-size field until newline or EOF without a le
- 8.1 High severity
urllib3: Improper Certificate Validation
urllib3 is an HTTP client library for Python. From 1.26.0 until 2.8.0, the proxy_ssl_context, proxy_assert_hostname, proxy_assert_fingerprint, ssl_context, cert_reqs, verify_mode, use_forwarding_for_https=True, and CERT_NONE configuration paths fail to remain
- 7.5 High severity
urllib3: Improper Handling of Highly Compressed Data (Data Amplification)
urllib3 is an HTTP client library for Python. From 2.6.0 to before 2.7.0, urllib3 could decompress the whole response instead of the requested portion (1) during the second HTTPResponse.read(amt=N) call when the response was decompressed using the official Bro
- 7.5 High severity
urllib3: Improper Handling of Highly Compressed Data (Data Amplification)
urllib3 is an HTTP client library for Python. urllib3's streaming API is designed for the efficient handling of large HTTP responses by reading the content in chunks, rather than loading the entire response body into memory at once. urllib3 can perform decodin
- 7.5 High severity
urllib3: Improper Handling of Highly Compressed Data (Data Amplification)
urllib3 is a user-friendly HTTP client library for Python. Starting in version 1.0 and prior to 2.6.0, the Streaming API improperly handles highly compressed data. urllib3's streaming API is designed for the efficient handling of large HTTP responses by readin
- 7.5 High severity
urllib3: Allocation of Resources Without Limits or Throttling
urllib3 is a user-friendly HTTP client library for Python. Starting in version 1.24 and prior to 2.6.0, the number of links in the decompression chain was unbounded allowing a malicious server to insert a virtually unlimited number of compression steps leading
- 8.1 High severity
urllib3: Exposure of Sensitive Information to an Unauthorized Actor
urllib3 is a user-friendly HTTP client library for Python. urllib3 doesn't treat the `Cookie` HTTP header special or provide any helpers for managing cookies over HTTP, that is the responsibility of the user. However, it is possible for a user to specify a `Co