GitHub Advisoryadvisory · PyPI

GHSA-mwh4-6h8g-pg8w AIOHTTP has HTTP response splitting via \r in reason phrase

LOW Published 2026-04-01 Modified 2026-04-01 Official page ↗
Aliases
CVE-2026-34519
Ecosystem
PyPI
Packages
aiohttp
Severity
Low
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U
Weaknesses
CWE-113
Reviewed
2026-04-01

Affected packages

• PyPI aiohttp: < 3.13.4 → fixed in 3.13.4

Description

Summary An attacker who controls the `reason` parameter when creating a `Response` may be able to inject extra headers or similar exploits. Impact In the unlikely situation that an application allows untrusted data to be used in the response's `reason` parameter, then an attacker could manipulate the response to send something different from what the developer intended. ----- Patch: https://github.com/aio-libs/aiohttp/commit/53b35a2f8869c37a133e60bf1a82a1c01642ba2b

Related

Alias · CVE (1)

  • CVE-2026-34519 AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. vulnerability

Weakness · CWE (1)

  • CWE-113 Improper Neutralization of CRLF Sequences in HTTP Headers weakness

References