# CVE-2026-84382

## Summary

- **CVE ID:** CVE-2026-84382
- **Severity:** HIGH
- **CVSS Score:** 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
- **CWE:** CWE-409
- **Published:** Sep 2, 2026
- **Last Modified:** Sep 3, 2026

## Description

HTTPX2 is a next generation HTTP client for Python. Prior to 2.12.0, the HTTPX2 content decoders in src/httpx2/httpx2/_decoders.py fully inflate each gzip, deflate, br, or zstd network chunk before iter_bytes() or aiter_bytes() yields bounded pieces to the application. A 64 KiB compressed chunk can expand to approximately 64 MiB in one intermediate allocation, so an attacker-controlled or compromised server can cause severe memory pressure or out-of-memory process termination even when the application streams the response. This issue is fixed in version 2.12.0.

## Affected Products

- pydantic — httpx2 (< 2.12.0)

## References

- [CNA](https://github.com/pydantic/httpx2/security/advisories/GHSA-8xx6-hgc6-gc2m)
- [CNA](https://github.com/pydantic/httpx2/pull/1126)
- [CNA](https://github.com/pydantic/httpx2/commit/4fd0c70a3f207c618b145934792f791bccfb39f8)
- [CNA](https://github.com/pydantic/httpx2/releases/tag/v2.12.0)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.35%
- **EPSS Percentile:** 28.2

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._