HTTP Response Splitting Affecting aiohttp package, versions [,3.13.4)
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- published2 Apr 2026
- disclosed1 Apr 2026
- creditDHIRAL2908
Introduced: 1 Apr 2026
NewCVE-2026-34519 (opens in a new tab)Common Vulnerabilities and Exposures (CVE) are common identifiers for publicly known security vulnerabilities
Common Weakness Enumeration (CWE) is a category system for software weaknesses
How to fix?
Upgrade aiohttp to version 3.13.4 or higher.
Overview
Affected versions of this package are vulnerable to HTTP Response Splitting via the reason parameter in the HTTP response creation process. An attacker can inject unauthorized headers or manipulate the HTTP response by supplying specially crafted input containing carriage return characters.