{"id":"CVE-2026-84382","state":"PUBLISHED","title":"HTTPX2: Streaming response decompression does not bound peak memory (decompression amplification)","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.","publishedAt":"2026-09-02T18:03:05.010Z","updatedAt":"2026-09-03T14:31:19.366Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["pydantic httpx2"],"affected":[{"vendor":"pydantic","product":"httpx2","versions":[{"version":"< 2.12.0","status":"affected"}]}],"references":["https://github.com/pydantic/httpx2/security/advisories/GHSA-8xx6-hgc6-gc2m","https://github.com/pydantic/httpx2/pull/1126","https://github.com/pydantic/httpx2/commit/4fd0c70a3f207c618b145934792f791bccfb39f8","https://github.com/pydantic/httpx2/releases/tag/v2.12.0"],"weaknesses":["CWE-409"],"ingestedAt":"2026-10-29T20:13:15.269Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/84xxx/CVE-2026-84382.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-84382","state":"PUBLISHED","datePublished":"2026-09-02T18:03:05.010Z","dateUpdated":"2026-09-03T14:31:19.366Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-09-01T16:27:58.130Z"},"containers":{"cna":{"title":"HTTPX2: Streaming response decompression does not bound peak memory (decompression amplification)","descriptions":[{"lang":"en","value":"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":[{"vendor":"pydantic","product":"httpx2","versions":[{"version":"< 2.12.0","status":"affected"}]}],"references":[{"url":"https://github.com/pydantic/httpx2/security/advisories/GHSA-8xx6-hgc6-gc2m","name":"https://github.com/pydantic/httpx2/security/advisories/GHSA-8xx6-hgc6-gc2m","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/pydantic/httpx2/pull/1126","name":"https://github.com/pydantic/httpx2/pull/1126","tags":["x_refsource_MISC"]},{"url":"https://github.com/pydantic/httpx2/commit/4fd0c70a3f207c618b145934792f791bccfb39f8","name":"https://github.com/pydantic/httpx2/commit/4fd0c70a3f207c618b145934792f791bccfb39f8","tags":["x_refsource_MISC"]},{"url":"https://github.com/pydantic/httpx2/releases/tag/v2.12.0","name":"https://github.com/pydantic/httpx2/releases/tag/v2.12.0","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":7.5,"baseSeverity":"HIGH","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-409","lang":"en","description":"CWE-409: Improper Handling of Highly Compressed Data (Data Amplification)","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-09-02T18:03:05.010Z"},"source":{"advisory":"GHSA-8xx6-hgc6-gc2m","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-03T14:09:07.115167Z","id":"CVE-2026-84382","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-03T14:31:19.366Z"}}]}}}