CVE-2026-84379

HTTPX2 , a next-generation HTTP client for Python, is affected by a multipart part header injection vulnerability in FileField.render_headers() within src/httpx2/httpx2/_multipart.py. Prior to 2.11.0 , attacker-controlled content_type values and custom headers from files= tuples are interpolated ...

CVE-2026-84378

HTTPX2 , a next-generation HTTP client for Python, is affected by a quadratic CPU denial-of-service vulnerability in its Server-Sent Events (SSE) parser. Versions from 2.5.0 through 2.10.0 are impacted. The root cause lies in _SSELineDecoder.decode() in src/httpx2/httpx2/_sse.py, which repeatedly...

CVE-2026-84378

HTTPX2 is a next generation HTTP client for Python. From 2.5.0 until 2.10.0, the HTTPX2 Server-Sent Events parser in src/httpx2/httpx2/sse.py repeatedly copies and rescans buffered text in SSELineDecoder.decode when an attacker-controlled or compromised SSE endpoint splits one unterminated line...

CVE-2026-84378 HTTPX2: Quadratic SSE line buffering can cause CPU denial of service

HTTPX2 is a next generation HTTP client for Python. From 2.5.0 until 2.10.0, the HTTPX2 Server-Sent Events parser in src/httpx2/httpx2/sse.py repeatedly copies and rescans buffered text in SSELineDecoder.decode when an attacker-controlled or compromised SSE endpoint splits one unterminated line...

CVE-2026-84378 HTTPX2: Quadratic SSE line buffering can cause CPU denial of service

HTTPX2 is a next generation HTTP client for Python. From 2.5.0 until 2.10.0, the HTTPX2 Server-Sent Events parser in src/httpx2/httpx2/sse.py repeatedly copies and rescans buffered text in SSELineDecoder.decode when an attacker-controlled or compromised SSE endpoint splits one unterminated line...

CVE-2026-84378 HTTPX2: Quadratic SSE line buffering can cause CPU denial of service

HTTPX2 is a next generation HTTP client for Python. From 2.5.0 until 2.10.0, the HTTPX2 Server-Sent Events parser in src/httpx2/httpx2/sse.py repeatedly copies and rescans buffered text in SSELineDecoder.decode when an attacker-controlled or compromised SSE endpoint splits one unterminated line...

PT-2026-84848

Name of the Vulnerable Software and Affected Versions httpcore2 versions prior to 2.10.0 HTTPX2 versions 2.6.0 through 2.9.1 Description An issue exists where TLS fails to start when a remote origin uses wss WebSocket Secure through a SOCKS5 proxy because the TLS upgrade condition only recognizes...

PT-2026-84849

Name of the Vulnerable Software and Affected Versions HTTPX2 versions prior to 2.12.0 Description Content decoders in src/httpx2/httpx2/ decoders.py fully inflate each gzip, deflate, br, or zstd network chunk before the iter bytes or aiter bytes functions yield bounded pieces to the application...

PT-2026-84846

Name of the Vulnerable Software and Affected Versions HTTPX2 versions prior to 2.11.0 Description The Request. prepare function in src/httpx2/httpx2/ models.py can add a body-derived Content-Length header to a request that already contains a caller-supplied Transfer-Encoding header. This occurs...

PT-2026-84845

Name of the Vulnerable Software and Affected Versions HTTPX2 versions prior to 2.11.0 Description The FileField.render headers function in src/httpx2/httpx2/ multipart.py fails to validate header names or values when interpolating content type values and custom headers from the files tuple. This...

PT-2026-84844

Name of the Vulnerable Software and Affected Versions HTTPX2 versions 2.5.0 through 2.9.0 Description The Server-Sent Events SSE parser in src/httpx2/httpx2/ sse.py repeatedly copies and rescans buffered text within the SSELineDecoder.decode function when an SSE endpoint splits a single...