CVE-2026-84382
CVE-2026-84382 is a high-severity vulnerability with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-409.
Key facts
- Severity: High (CVSS 3.x base score 7.5)
- EPSS exploit prediction: 1% (48th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-409
- Published:
- Last modified:
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.
Frequently asked questions
- What is CVE-2026-84382?
- 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.
- How severe is CVE-2026-84382?
- CVE-2026-84382 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
- Is CVE-2026-84382 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (48th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-84382?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2026-84382 published?
- CVE-2026-84382 was published on 2026-09-02 and last updated on 2026-09-09.
References
- https://github.com/pydantic/httpx2/commit/4fd0c70a3f207c618b145934792f791bccfb39f8
- https://github.com/pydantic/httpx2/pull/1126
- https://github.com/pydantic/httpx2/releases/tag/v2.12.0
- https://github.com/pydantic/httpx2/security/advisories/GHSA-8xx6-hgc6-gc2m
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