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Security Advisories

CVE-2026-34520

NVD

https://nvd.nist.gov/vuln/detail/CVE-2026-34520

Severity

Unknown
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Summary

AIOHTTP: C parser (llhttp) accepts null bytes and control characters in response header values - header injection / security bypass

Description

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, the C parser (the default for most installs) accepted null bytes and control characters in response headers. This issue has been patched in version 3.13.4.

References

Affected packages

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