Client interruption via unbounded error-pointer read
Published Aug 3, 2026 · Updated Aug 3, 2026
Out-of-bounds read in aiohttp before 3.14.3 allows remote attackers controlling an HTTP server to interrupt a client with a malformed response. In aiohttp/_http_parser.pyx, Cython materializes bytes from the raw llhttp error-position pointer while composing a parse-error snippet, allowing a read beyond the supplied buffer. The client must use the C extension and connect to the attacker-controlled server; the pure-Python parser is unaffected, and no data modification is reported.
Summary
What happened
Out-of-bounds read in aiohttp before 3.14.3 allows remote attackers controlling an HTTP server to interrupt a client with a malformed response. In aiohttp/_http_parser.pyx, Cython materializes bytes from the raw llhttp error-position pointer while composing a parse-error snippet, allowing a read beyond the supplied buffer. The client must use the C extension and connect to the attacker-controlled server; the pure-Python parser is unaffected, and no data modification is reported.
The record
- CVE
- CVE-2026-69244
- Published
- Aug 3, 2026
- Updated
- Aug 3, 2026
- Vendor
- aio-libs
- Product
- aiohttp
- Classifications
- CWE-416, CWE-400, CWE-125, T1499
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 3, 2026CVE publishedPublication date reported by the CVE source.
- Aug 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=< 3.14.3
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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