CVE-2026-34519

AIOHTTP: HTTP response splitting via \r in reason phrase

State
Published
Severity
2.7 Low
Published
Apr 1, 2026
Updated
Apr 2, 2026
Reserved
Mar 30, 2026

Read the record on cve.org

Description

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, an attacker who controls the reason parameter when creating a Response may be able to inject extra headers or similar exploits. This issue has been patched in version 3.13.4.

Scores

CVSSScoreVectorSource
4.02.7 LowCVSS: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:UGitHub_M

Weaknesses

  • CWE-113 Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')

Affected Products

ProductVersions
aiohttpaio-libs
  • < 3.13.4Affected

References

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.