GHSA-8xx6-hgc6-gc2m: httpx2 (CVE-2026-84382)

Package	Ecosystem	Affected	Fixed in
httpx2	PyPI	<2.12.0	2.12.0

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

HTTPX2 versions before 2.12.0 are affected. When a compressed response (gzip, deflate, br, or zstd) was read, the library fully decompressed each network chunk into one intermediate allocation before yielding content, so a small malicious compressed response could cause large memory use even when streamed. An attacker who can get the application to fetch from a server they control needs no authentication or user interaction. Upgrade to httpx2 2.12.0 or later, which decompresses incrementally with bounded buffers.

Written 1 Nov 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
7.5	High	3.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	CNA (GitHub_M)

CISA KEV Not listed.
EPSS 0.0063, the 50th percentile, on 6 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

31 Oct 2026, 14:10 UTC First seen by agentprime
31 Oct 2026, 14:10 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.