aiohttp's ClientSession is vulnerable to CRLF injection via method

Summary

CVECVE-2023-49082
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2023-11-29 20:15:08 UTC
Updated2026-06-23 18:17:35 UTC
Descriptionaiohttp is an asynchronous HTTP client/server framework for asyncio and Python. Improper validation makes it possible for an attacker to modify the HTTP request (e.g. insert a new header) or even create a new HTTP request if the attacker controls the HTTP method. The vulnerability occurs only if the attacker can control the HTTP method (GET, POST etc.) of the request. If the attacker can control the HTTP version of the request it will be able to modify the request (request smuggling). This issue has been patched in version 3.9.0.

Risk And Classification

Primary CVSS: v3.1 5.3 MEDIUM from [email protected]

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

EPSS: 0.009400000 probability, percentile 0.564540000 (date 2026-06-28)

Problem Types: CWE-20 | CWE-93 | CWE-93 CWE-93: Improper Neutralization of CRLF Sequences ('CRLF Injection') | CWE-20 CWE-20: Improper Input Validation


VersionSourceTypeScoreSeverityVector
3.1[email protected]Primary5.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
3.1[email protected]Secondary5.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
3.1CNADECLARED5.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Aiohttp Aiohttp All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Aio-libs Aiohttp affected < 3.9.0 Not specified

References

ReferenceSourceLinkTags
github.com/aio-libs/aiohttp/security/advisories/GHSA-qvrw-v9rv-5rjx af854a3a-2127-422b-91ae-364da2661108 github.com Exploit, Vendor Advisory
Add HTTP method validation (#6533) (#7806) · aio-libs/aiohttp@e4ae01c · GitHub af854a3a-2127-422b-91ae-364da2661108 github.com
lists.fedoraproject.org/archives/list/[email protected]/messag... af854a3a-2127-422b-91ae-364da2661108 lists.fedoraproject.org
Add HTTP method validation (#6533) by Dreamsorcerer · Pull Request #7806 · aio-libs/aiohttp · GitHub af854a3a-2127-422b-91ae-364da2661108 github.com
gist.github.com/jnovikov/7f411ae9fe6a9a7804cf162a3bdbb44b af854a3a-2127-422b-91ae-364da2661108 gist.github.com Exploit, Third Party Advisory
lists.debian.org/debian-lts-announce/2025/02/msg00002.html af854a3a-2127-422b-91ae-364da2661108 lists.debian.org
:https://lists.fedoraproject.org/archives/list/[email protected]/message/TY5SI6NK5243DEEDQUFKQKW5GQNKQUMA/ MITRE lists.fedoraproject.org
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Legacy QID Mappings

  • 285071 Fedora Security Update for python (FEDORA-2023-a04cc349e1)
  • 755634 SUSE Enterprise Linux Security Update for python-aiohttp (SUSE-SU-2024:0168-1)
  • 996079 Python (Pip) Security Update for aiohttp (GHSA-qvrw-v9rv-5rjx)
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