CVE-2025-66418 — urllib3 allows an unbounded number of links in the decompression chain
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 m…
Published: 2025-12-05 · CVSS: 8.9 · CVSS 4.0
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 and massive memory allocation for the decompressed data. This vulnerability is fixed in 2.6.0.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7