Sourced from urllib3's releases.
2.6.3
🚀 urllib3 is fundraising for HTTP/2 support
urllib3 is raising ~$40,000 USD to release HTTP/2 support and ensure long-term sustainable maintenance of the project after a sharp decline in financial support. If your company or organization uses Python and would benefit from HTTP/2 support in Requests, pip, cloud SDKs, and thousands of other projects please consider contributing financially to ensure HTTP/2 support is developed sustainably and maintained for the long-haul.
Thank you for your support.
Changes
- Fixed a security issue where decompression-bomb safeguards of the streaming API were bypassed when HTTP redirects were followed. (CVE-2026-21441 reported by
@​D47A, 8.9 High, GHSA-38jv-5279-wg99)- Started treating
Retry-Aftertimes greater than 6 hours as 6 hours by default. (urllib3/urllib3#3743)- Fixed
urllib3.connection.VerifiedHTTPSConnectionon Emscripten. (urllib3/urllib3#3752)2.6.2
🚀 urllib3 is fundraising for HTTP/2 support
urllib3 is raising ~$40,000 USD to release HTTP/2 support and ensure long-term sustainable maintenance of the project after a sharp decline in financial support. If your company or organization uses Python and would benefit from HTTP/2 support in Requests, pip, cloud SDKs, and thousands of other projects please consider contributing financially to ensure HTTP/2 support is developed sustainably and maintained for the long-haul.
Thank you for your support.
Changes
- Fixed
HTTPResponse.read_chunked()to properly handle leftover data in the decoder's buffer when reading compressed chunked responses. (urllib3/urllib3#3734)2.6.1
🚀 urllib3 is fundraising for HTTP/2 support
urllib3 is raising ~$40,000 USD to release HTTP/2 support and ensure long-term sustainable maintenance of the project after a sharp decline in financial support. If your company or organization uses Python and would benefit from HTTP/2 support in Requests, pip, cloud SDKs, and thousands of other projects please consider contributing financially to ensure HTTP/2 support is developed sustainably and maintained for the long-haul.
Thank you for your support.
Changes
- Restore previously removed
HTTPResponse.getheaders()andHTTPResponse.getheader()methods. (#3731)
Sourced from urllib3's changelog.
2.6.3 (2026-01-07)
- Fixed a high-severity security issue where decompression-bomb safeguards of the streaming API were bypassed when HTTP redirects were followed. (
GHSA-38jv-5279-wg99 <https://github.com/urllib3/urllib3/security/advisories/GHSA-38jv-5279-wg99>__)- Started treating
Retry-Aftertimes greater than 6 hours as 6 hours by default. ([#3743](https://github.com/urllib3/urllib3/issues/3743) <https://github.com/urllib3/urllib3/issues/3743>__)- Fixed
urllib3.connection.VerifiedHTTPSConnectionon Emscripten. ([#3752](https://github.com/urllib3/urllib3/issues/3752) <https://github.com/urllib3/urllib3/issues/3752>__)2.6.2 (2025-12-11)
- Fixed
HTTPResponse.read_chunked()to properly handle leftover data in the decoder's buffer when reading compressed chunked responses. ([#3734](https://github.com/urllib3/urllib3/issues/3734) <https://github.com/urllib3/urllib3/issues/3734>__)2.6.1 (2025-12-08)
- Restore previously removed
HTTPResponse.getheaders()andHTTPResponse.getheader()methods. ([#3731](https://github.com/urllib3/urllib3/issues/3731) <https://github.com/urllib3/urllib3/issues/3731>__)
0248277
Release 2.6.38864ac4
Merge commit from fork70cecb2
Fix Scorecard issues related to vulnerable dev dependencies (#3755)41f249a
Move "v2.0 Migration Guide" to the end of the table of
contents (#3747)fd4dffd
Patch VerifiedHTTPSConnection for Emscripten (#3752)13f0bfd
Handle massive values in Retry-After when calculating time to sleep for
(#3743)8c480bf
Bump actions/upload-artifact from 5.0.0 to 6.0.0 (#3748)4b40616
Bump actions/cache from 4.3.0 to 5.0.1 (#3750)82b8479
Bump actions/download-artifact from 6.0.0 to 7.0.0 (#3749)34284cb
Mention experimental features in the security policy (#3746)