aiohttp's ClientSession is vulnerable to CRLF injection via version

Summary

CVECVE-2023-49081
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2023-11-30 07:15:08 UTC
Updated2026-06-23 18:17:35 UTC
Descriptionaiohttp is an asynchronous HTTP client/server framework for asyncio and Python. Improper validation made it possible for an attacker to modify the HTTP request (e.g. to insert a new header) or create a new HTTP request if the attacker controls the HTTP version. The vulnerability only occurs if the attacker can control the HTTP version of the request. 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: 0.008740000 probability, percentile 0.543890000 (date 2026-06-28)

Problem Types: CWE-20 | NVD-CWE-Other | 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]Secondary7.2HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
3.1CNADECLARED7.2HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/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
gist.github.com/jnovikov/184afb593d9c2114d77f508e0ccd508e af854a3a-2127-422b-91ae-364da2661108 gist.github.com Exploit, Third Party Advisory
Disallow arbitrary sequence types in version by Dreamsorcerer · Pull Request #7835 · aio-libs/aiohttp · GitHub af854a3a-2127-422b-91ae-364da2661108 github.com
github.com/aio-libs/aiohttp/security/advisories/GHSA-q3qx-c6g2-7pw2 af854a3a-2127-422b-91ae-364da2661108 github.com Exploit, Vendor Advisory
lists.fedoraproject.org/archives/list/[email protected]/messag... af854a3a-2127-422b-91ae-364da2661108 lists.fedoraproject.org
lists.debian.org/debian-lts-announce/2025/02/msg00002.html af854a3a-2127-422b-91ae-364da2661108 lists.debian.org
Disallow arbitrary sequence types in version (#7835) · aio-libs/aiohttp@1e86b77 · GitHub af854a3a-2127-422b-91ae-364da2661108 github.com
: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

  • 243144 Red Hat Update for Satellite 6.14.3 (RHSA-2024:1536)
  • 285071 Fedora Security Update for python (FEDORA-2023-a04cc349e1)
  • 755577 SUSE Enterprise Linux Security Update for python-aiohttp (SUSE-SU-2024:0033-1)
  • 755578 SUSE Enterprise Linux Security Update for python-aiohttp (SUSE-SU-2024:0034-1)
  • 996077 Python (Pip) Security Update for aiohttp (GHSA-q3qx-c6g2-7pw2)
  • 996318 Python (Pip) Security Update for meraki (GHSA-6x4h-9622-fqr6)
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