Service interruption via unbounded reset-stream queue
Published Apr 11, 2023 · Updated Feb 11, 2025
Denial of service in Hyperium h2 before 0.3.17 allows remote attackers to exhaust server memory with HEADERS and RST_STREAM floods. Reset streams closed before acceptance remain in the pending accept queue and consume slab memory without counting toward the concurrent-stream limit. Exploitation requires an HTTP/2 connection and enough traffic to outpace the server's accept loop, causing excessive memory use and eventual out-of-memory failure.
Summary
What happened
Denial of service in Hyperium h2 before 0.3.17 allows remote attackers to exhaust server memory with HEADERS and RST_STREAM floods. Reset streams closed before acceptance remain in the pending accept queue and consume slab memory without counting toward the concurrent-stream limit. Exploitation requires an HTTP/2 connection and enough traffic to outpace the server's accept loop, causing excessive memory use and eventual out-of-memory failure.
The record
- CVE
- CVE-2023-26964
- Published
- Apr 11, 2023
- Updated
- Feb 11, 2025
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-770, T1499
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 11, 2023CVE publishedPublication date reported by the CVE source.
- Feb 11, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- HEADERS and RST_STREAM reset-flood proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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