CVE-2026-34520

A flaw was found in AIOHTTP, an asynchronous HTTP client/server framework for Python. The default C parser incorrectly processed null bytes and control characters present in HTTP response headers. This vulnerability could allow a remote attacker to inject malicious data into these headers,...

EUVD-2026-18046

AIOHTTP's C parser llhttp accepts null bytes and control characters in response header values - header injection/security bypass...

GHSA-63HF-3VF5-4WQF AIOHTTP's C parser (llhttp) accepts null bytes and control characters in response header values - header injection/security bypass

Summary The C parser the default for most installs accepted null bytes and control characters in request headers. Impact An attacker could send header values that are interpreted differently than expected due to the presence of control characters. For example, request.url.origin may return a...

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

Summary The C parser the default for most installs accepted null bytes and control characters in request headers. Impact An attacker could send header values that are interpreted differently than expected due to the presence of control characters. For example, request.url.origin may return a...

CVE-2026-34520

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...

CVE-2026-34520

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...

PYSEC-2026-2102

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...

PYSEC-2026-2102

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...

DEBIAN-CVE-2026-34520

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...

AZL-81779 CVE-2026-34520 affecting package python-aiohttp 3.6.2-3

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...

CVE-2026-34520

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...

CVE-2026-34520 AIOHTTP: C parser (llhttp) accepts null bytes and control characters in response header values - header injection / security bypass

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...

CVE-2026-34520

The aiohttp asynchronous HTTP client/server framework for Python and asyncio is vulnerable to a security bypass and header injection due to a flaw in its C parser (the default for most installations). Specifically, the parser accepts null bytes and control characters in response headers, allowing...

CVE-2026-34520

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...

CVE-2026-34520 AIOHTTP: C parser (llhttp) accepts null bytes and control characters in response header values - header injection / security bypass

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...

CVE-2026-34520

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...

CVE-2026-34520 AIOHTTP: C parser (llhttp) accepts null bytes and control characters in response header values - header injection / security bypass

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...

Improper Certificate Validation

github.com/envoyproxy/envoy is vulnerable to improper certificate validation. The vulnerability is due to incorrect handling of embedded null bytes \0 in OTHERNAME SAN values within mTLS certificate matching, which allows an attacker to bypass certificate validation and achieve unauthorized acces...

Out-of-bounds Read

Overview Affected versions of this package are vulnerable to Out-of-bounds Read in the uclobjectemit function when operating in UCLPARSERZEROCOPY mode and processing input containing a key with an embedded null byte. An attacker can cause a segmentation fault and disrupt service by submitting...

PT-2026-29609

Name of the Vulnerable Software and Affected Versions AIOHTTP versions prior to 3.13.4 Description The C parser, used by default in most installations, allowed null bytes and control characters within response headers. An attacker could leverage this to send header values that are interpreted...