Описание
urllib3 version 2.6.3 is vulnerable to a decompression bomb bypass in its streaming API (preload_content=False) when using Brotli support. The issue arises due to three independent code paths in response.py that bypass the max_length protection introduced in version 2.6.0 to mitigate CVE-2025-66471. Specifically, negative max_length values can be produced due to buffer arithmetic in read(), flush_decoder unconditionally overrides max_length to -1, and _flush_decoder() passes no limit at all, defaulting to unlimited decompression. This allows a malicious HTTP server to trigger an out-of-memory (OOM) condition by decompressing large payloads into memory, leading to a denial of service (DoS). The vulnerability affects urllib3 2.6.3 and Brotli 1.2.0 and impacts applications and libraries using requests or urllib3 to stream content from untrusted sources.
urllib3 version 2.6.3 is vulnerable to a decompression bomb bypass in its streaming API (preload_content=False) when using Brotli support. The issue arises due to three independent code paths in response.py that bypass the max_length protection introduced in version 2.6.0 to mitigate CVE-2025-66471. Specifically, negative max_length values can be produced due to buffer arithmetic in read(), flush_decoder unconditionally overrides max_length to -1, and _flush_decoder() passes no limit at all, defaulting to unlimited decompression. This allows a malicious HTTP server to trigger an out-of-memory (OOM) condition by decompressing large payloads into memory, leading to a denial of service (DoS). The vulnerability affects urllib3 2.6.3 and Brotli 1.2.0 and impacts applications and libraries using requests or urllib3 to stream content from untrusted sources.
Связанные уязвимости
Rejected reason: This CVE ID has been rejected or withdrawn by its CVE Numbering Authority.
Rejected reason: This CVE ID has been rejected or withdrawn by its CVE Numbering Authority.
