CVEvulnerability

CVE-2026-84378

5.9 MEDIUM Published 2026-09-02 Modified 2026-09-09 Official page ↗
Status
Awaiting Analysis
Published
2026-09-02
Last modified
2026-09-09
Assigner
[email protected]
CVSS 3.1 ([email protected])
5.9 MEDIUM — CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Weaknesses
CWE-407

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.

Related

Weakness · CWE (1)

  • CWE-407 Inefficient Algorithmic Complexity weakness

References