PyPI package
urllib3
pkg:pypi/urllib3
Vulnerabilities (19)
| CVE | Sev | CVSS | KEV | Affected versions | Fixed in | Published | Description |
|---|---|---|---|---|---|---|---|
| CVE-2026-44432 | Hig | 7.5 | >= 2.6.0, < 2.7.0 | 2.7.0 | May 13, 2026 | 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 Brotli library or (2) w | |
| CVE-2026-44431 | Med | 5.3 | >= 1.23, < 2.7.0 | 2.7.0 | May 13, 2026 | urllib3 is an HTTP client library for Python. From 1.23 to before 2.7.0, cross-origin redirects followed from the low-level API via ProxyManager.connection_from_url().urlopen(..., assert_same_host=False) still forward these sensitive headers. This vulnerability is fixed in 2.7.0. | |
| CVE-2026-21441 | — | >= 1.22, < 2.6.3 | 2.6.3 | Jan 7, 2026 | 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 decoding or decompression b | ||
| CVE-2025-66471 | — | >= 1.0, < 2.6.0 | 2.6.0 | Dec 5, 2025 | 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 reading the content in chu | ||
| CVE-2025-66418 | — | >= 1.24, < 2.6.0 | 2.6.0 | Dec 5, 2025 | 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 to high CPU usage a | ||
| CVE-2025-50182 | — | >= 2.2.0, < 2.5.0 | 2.5.0 | Jun 19, 2025 | urllib3 is a user-friendly HTTP client library for Python. Starting in version 2.2.0 and prior to 2.5.0, urllib3 does not control redirects in browsers and Node.js. urllib3 supports being used in a Pyodide runtime utilizing the JavaScript Fetch API or falling back on XMLHttpReque | ||
| CVE-2025-50181 | — | < 2.5.0 | 2.5.0 | Jun 19, 2025 | urllib3 is a user-friendly HTTP client library for Python. Prior to 2.5.0, it is possible to disable redirects for all requests by instantiating a PoolManager and specifying retries in a way that disable redirects. By default, requests and botocore users are not affected. An appl | ||
| CVE-2024-37891 | — | < 1.26.19 | 1.26.19 | Jun 17, 2024 | urllib3 is a user-friendly HTTP client library for Python. When using urllib3's proxy support with `ProxyManager`, the `Proxy-Authorization` header is only sent to the configured proxy, as expected. However, when sending HTTP requests *without* using urllib3's proxy support, it' | ||
| CVE-2023-45803 | — | >= 2.0.0, < 2.0.7 | 2.0.7 | Oct 17, 2023 | urllib3 is a user-friendly HTTP client library for Python. urllib3 previously wouldn't remove the HTTP request body when an HTTP redirect response using status 301, 302, or 303 after the request had its method changed from one that could accept a request body (like `POST`) to `GE | ||
| CVE-2018-25091 | — | < 1.24.2 | 1.24.2 | Oct 15, 2023 | urllib3 before 1.24.2 does not remove the authorization HTTP header when following a cross-origin redirect (i.e., a redirect that differs in host, port, or scheme). This can allow for credentials in the authorization header to be exposed to unintended hosts or transmitted in clea | ||
| CVE-2023-43804 | — | >= 2.0.0, < 2.0.6 | 2.0.6 | Oct 4, 2023 | 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 `Cookie` header and unk | ||
| CVE-2021-33503 | — | >= 1.25.4, < 1.26.5 | 1.26.5 | Jun 29, 2021 | An issue was discovered in urllib3 before 1.26.5. When provided with a URL containing many @ characters in the authority component, the authority regular expression exhibits catastrophic backtracking, causing a denial of service if a URL were passed as a parameter or redirected t | ||
| CVE-2021-28363 | — | >= 1.26.0, < 1.26.4 | 1.26.4 | Mar 15, 2021 | The urllib3 library 1.26.x before 1.26.4 for Python omits SSL certificate validation in some cases involving HTTPS to HTTPS proxies. The initial connection to the HTTPS proxy (if an SSLContext isn't given via proxy_config) doesn't verify the hostname of the certificate. This mean | ||
| CVE-2020-26137 | — | < 1.25.9 | 1.25.9 | Sep 29, 2020 | urllib3 before 1.25.9 allows CRLF injection if the attacker controls the HTTP request method, as demonstrated by inserting CR and LF control characters in the first argument of putrequest(). NOTE: this is similar to CVE-2020-26116. | ||
| CVE-2020-7212 | — | >= 1.25.2, < 1.25.8 | 1.25.8 | Mar 6, 2020 | The _encode_invalid_chars function in util/url.py in the urllib3 library 1.25.2 through 1.25.7 for Python allows a denial of service (CPU consumption) because of an inefficient algorithm. The percent_encodings array contains all matches of percent encodings. It is not deduplicate | ||
| CVE-2019-11324 | — | < 1.24.2 | 1.24.2 | Apr 18, 2019 | The urllib3 library before 1.24.2 for Python mishandles certain cases where the desired set of CA certificates is different from the OS store of CA certificates, which results in SSL connections succeeding in situations where a verification failure is the correct outcome. This is | ||
| CVE-2019-11236 | — | < 1.24.3 | 1.24.3 | Apr 15, 2019 | In the urllib3 library through 1.24.1 for Python, CRLF injection is possible if the attacker controls the request parameter. | ||
| CVE-2018-20060 | — | < 1.23 | 1.23 | Dec 11, 2018 | urllib3 before version 1.23 does not remove the Authorization HTTP header when following a cross-origin redirect (i.e., a redirect that differs in host, port, or scheme). This can allow for credentials in the Authorization header to be exposed to unintended hosts or transmitted i | ||
| CVE-2016-9015 | Low | 3.7 | >= 1.17, < 1.18.1 | 1.18.1 | Jan 11, 2017 | Versions 1.17 and 1.18 of the Python urllib3 library suffer from a vulnerability that can cause them, in certain configurations, to not correctly validate TLS certificates. This places users of the library with those configurations at risk of man-in-the-middle and information lea |
- affected >= 2.6.0, < 2.7.0fixed 2.7.0
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 Brotli library or (2) w
- affected >= 1.23, < 2.7.0fixed 2.7.0
urllib3 is an HTTP client library for Python. From 1.23 to before 2.7.0, cross-origin redirects followed from the low-level API via ProxyManager.connection_from_url().urlopen(..., assert_same_host=False) still forward these sensitive headers. This vulnerability is fixed in 2.7.0.
- CVE-2026-21441Jan 7, 2026affected >= 1.22, < 2.6.3fixed 2.6.3
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 decoding or decompression b
- CVE-2025-66471Dec 5, 2025affected >= 1.0, < 2.6.0fixed 2.6.0
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 reading the content in chu
- CVE-2025-66418Dec 5, 2025affected >= 1.24, < 2.6.0fixed 2.6.0
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 to high CPU usage a
- CVE-2025-50182Jun 19, 2025affected >= 2.2.0, < 2.5.0fixed 2.5.0
urllib3 is a user-friendly HTTP client library for Python. Starting in version 2.2.0 and prior to 2.5.0, urllib3 does not control redirects in browsers and Node.js. urllib3 supports being used in a Pyodide runtime utilizing the JavaScript Fetch API or falling back on XMLHttpReque
- CVE-2025-50181Jun 19, 2025affected < 2.5.0fixed 2.5.0
urllib3 is a user-friendly HTTP client library for Python. Prior to 2.5.0, it is possible to disable redirects for all requests by instantiating a PoolManager and specifying retries in a way that disable redirects. By default, requests and botocore users are not affected. An appl
- CVE-2024-37891Jun 17, 2024affected < 1.26.19fixed 1.26.19
urllib3 is a user-friendly HTTP client library for Python. When using urllib3's proxy support with `ProxyManager`, the `Proxy-Authorization` header is only sent to the configured proxy, as expected. However, when sending HTTP requests *without* using urllib3's proxy support, it'
- CVE-2023-45803Oct 17, 2023affected >= 2.0.0, < 2.0.7fixed 2.0.7
urllib3 is a user-friendly HTTP client library for Python. urllib3 previously wouldn't remove the HTTP request body when an HTTP redirect response using status 301, 302, or 303 after the request had its method changed from one that could accept a request body (like `POST`) to `GE
- CVE-2018-25091Oct 15, 2023affected < 1.24.2fixed 1.24.2
urllib3 before 1.24.2 does not remove the authorization HTTP header when following a cross-origin redirect (i.e., a redirect that differs in host, port, or scheme). This can allow for credentials in the authorization header to be exposed to unintended hosts or transmitted in clea
- CVE-2023-43804Oct 4, 2023affected >= 2.0.0, < 2.0.6fixed 2.0.6
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 `Cookie` header and unk
- CVE-2021-33503Jun 29, 2021affected >= 1.25.4, < 1.26.5fixed 1.26.5
An issue was discovered in urllib3 before 1.26.5. When provided with a URL containing many @ characters in the authority component, the authority regular expression exhibits catastrophic backtracking, causing a denial of service if a URL were passed as a parameter or redirected t
- CVE-2021-28363Mar 15, 2021affected >= 1.26.0, < 1.26.4fixed 1.26.4
The urllib3 library 1.26.x before 1.26.4 for Python omits SSL certificate validation in some cases involving HTTPS to HTTPS proxies. The initial connection to the HTTPS proxy (if an SSLContext isn't given via proxy_config) doesn't verify the hostname of the certificate. This mean
- CVE-2020-26137Sep 29, 2020affected < 1.25.9fixed 1.25.9
urllib3 before 1.25.9 allows CRLF injection if the attacker controls the HTTP request method, as demonstrated by inserting CR and LF control characters in the first argument of putrequest(). NOTE: this is similar to CVE-2020-26116.
- CVE-2020-7212Mar 6, 2020affected >= 1.25.2, < 1.25.8fixed 1.25.8
The _encode_invalid_chars function in util/url.py in the urllib3 library 1.25.2 through 1.25.7 for Python allows a denial of service (CPU consumption) because of an inefficient algorithm. The percent_encodings array contains all matches of percent encodings. It is not deduplicate
- CVE-2019-11324Apr 18, 2019affected < 1.24.2fixed 1.24.2
The urllib3 library before 1.24.2 for Python mishandles certain cases where the desired set of CA certificates is different from the OS store of CA certificates, which results in SSL connections succeeding in situations where a verification failure is the correct outcome. This is
- CVE-2019-11236Apr 15, 2019affected < 1.24.3fixed 1.24.3
In the urllib3 library through 1.24.1 for Python, CRLF injection is possible if the attacker controls the request parameter.
- CVE-2018-20060Dec 11, 2018affected < 1.23fixed 1.23
urllib3 before version 1.23 does not remove the Authorization HTTP header when following a cross-origin redirect (i.e., a redirect that differs in host, port, or scheme). This can allow for credentials in the Authorization header to be exposed to unintended hosts or transmitted i
- affected >= 1.17, < 1.18.1fixed 1.18.1
Versions 1.17 and 1.18 of the Python urllib3 library suffer from a vulnerability that can cause them, in certain configurations, to not correctly validate TLS certificates. This places users of the library with those configurations at risk of man-in-the-middle and information lea