Process termination via unbounded streaming decompression
Published Sep 2, 2026 · Updated Sep 3, 2026
Denial of service in Pydantic HTTPX2 before 2.12.0 allows remote attackers to terminate applications via compressed responses. The content decoders fully inflate each gzip, deflate, Brotli, or Zstandard network chunk into one intermediate allocation before yielding bounded pieces. Exploitation requires an application to fetch an attacker-controlled or compromised server; the bounded consequence is memory pressure or out-of-memory termination.
Summary
What happened
Denial of service in Pydantic HTTPX2 before 2.12.0 allows remote attackers to terminate applications via compressed responses. The content decoders fully inflate each gzip, deflate, Brotli, or Zstandard network chunk into one intermediate allocation before yielding bounded pieces. Exploitation requires an application to fetch an attacker-controlled or compromised server; the bounded consequence is memory pressure or out-of-memory termination.
The record
- CVE
- CVE-2026-84382
- Published
- Sep 2, 2026
- Updated
- Sep 3, 2026
- Vendor
- Pydantic
- Product
- HTTPX2
- Classifications
- CWE-409, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 2, 2026CVE publishedPublication date reported by the CVE source.
- Sep 3, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 2.12.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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