VULNpocalypse

CVE-2026-69243: AIOHTTP: HTTP request smuggling via WebSocket upgrade

Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.

Generated by VEDAS. Scores as of 2026-11-01 19:19 UTC. Rebuilt every few hours from cve-scores, CISA KEV and vedas-signatures. How this works and its limits.

What it is

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.2, the HTTP parsers were vulnerable to a request smuggling attack relating to WebSocket upgrades. If using the server-side component, an attacker may be able to execute a request smuggling vulnerability using an edge case in the WebSocket upgrade procedure. A WebSocket upgrade request with a body could cause the parser to switch protocols before the complete request body was received, leaving trailing bytes to be handled as upgraded-protocol or pipelined data rather than normal HTTP body data. This issue is fixed in version 3.14.2.

Description quoted from the CVE record (assigned by GitHub_M, published 2026-08-03).

Weakness: CWE-444: Inconsistent Interpretation of HTTP Requests (‘HTTP Request/Response Smuggling’)

How it can be exploited

Exploitable over the network with high attack complexity with no special attack requirements needing no privileges and no user interaction. Impact: confidentiality none, integrity low, availability none. CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

CISA assessment (SSVC): CISA has no evidence of exploitation. Automatable: no. Technical impact: partial.

Public exploit evidence (Exploit Observer)

Also known as: BDU:2026-11139, EUVD-2026-52436, GHSA-mfx4-hv73-q22v

VEDAS cluster: VEDAS:DARKVECTORS

Exploit Observer links 4 pieces of public exploit code or detection modules that name this CVE or one of its aliases.

Exploit code and modules (4)

Code that names this CVE. A repository can be a working exploit, a scanner, a fake or malware; read it before running anything.

Vulnerability databases and vendor advisories (9)

Catalogue entries, not exploit evidence.

20 more references returned by Exploit Observer did not name this CVE or an alias, so they are left out.

VEDAS data as of 2026-11-01T17:12 UTC; fetched 2026-11-02.

Live scores

EPSS
0.004
low predicted chance of attack
VEDAS
0.986
strong exploit evidence
On CISA KEV
Not listed
Detection rule
Suricata

Who is affected

ProductAffectedNot affected
aio-libs aiohttpversion < 3.14.2Not stated

Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.

Exploit Observer also maps it to: pypi aiohttp, сообщество_свободного_программного_обеспечения aiohttp.

How to fix it

No fixed version or vendor advisory is listed in the CVE record yet. Watch the vendor’s security page.

How to detect it

Suricata rules (network detection)

1 rule that alert on traffic matching this exploit: VEDAS CVE-2026-69243 aiohttp WebSocket Upgrade HTTP Request Smuggling. Add them to your Suricata rule set and reload.

Show the rules
suricata
# CVE-2026-69243 - aiohttp (< 3.14.2) server-side HTTP request smuggling via the
# WebSocket upgrade path (CWE-444): a GET request carrying "Upgrade: websocket" plus a
# non-empty body (Content-Length > 0) makes the parser switch protocols before the body
# is consumed, so the smuggled bytes in the body are treated as a second/pipelined request.
# A legitimate WebSocket handshake carries no request body, so an upgrade request with a
# non-zero Content-Length is the anomaly.
alert http $EXTERNAL_NET any -> $HTTP_SERVERS $HTTP_PORTS (msg:"VEDAS CVE-2026-69243 aiohttp WebSocket Upgrade HTTP Request Smuggling"; flow:established,to_server; http.method; content:"GET"; http.header; content:"websocket"; nocase; fast_pattern; content:"Upgrade"; nocase; content:"Content-Length"; nocase; pcre:"/^Upgrade\x3a\x20*websocket/Hmi"; pcre:"/^Content-Length\x3a\x20*0*[1-9]/Hmi"; classtype:web-application-attack; reference:cve,CVE-2026-69243; reference:url,https://www.exploit.observer/?keyword=CVE-2026-69243&match=exact; reference:url,https://subdomain.center/?engine=ammonites&keyword=aiohttp&match=exact; sid:1091000; rev:1;)

CVE-2026-69243.rules on GitHub

References

Other references

Other databases

Where this comes from

This advisory is generated automatically by VEDAS from: CVE.org record, cve-scores (EPSS and VEDAS), Exploit Observer, vedas-signatures. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.