5.9
Medium
CVE-2026-84378 HTTPX2 is a next generation HTTP client for Python
Description
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 across many response chunks. The behavior affects httpx2.Client.sse() and httpx2.AsyncClient.sse(), and the total processing work grows quadratically with the line length, allowing a crafted stream to consume excessive CPU and block a synchronous worker or asynchronous event loop. This issue is fixed in version 2.10.0.
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| httpx2 2.5 | 2.5.0 → < 2.10.0 | 2.10.0 |
Other CVEs of httpx2
The 5 CVEs of httpx2 →
CVE-2026-84382
HTTPX2 is a next generation HTTP client for Python
7.5
High
CVE-2026-84381
HTTPX2 is a next generation HTTP client for Python
8.1
High
CVE-2026-84380
HTTPX2 is a next generation HTTP client for Python
5.6
Medium
CVE-2026-84379
HTTPX2 is a next generation HTTP client for Python
5.3
Medium