CVE-2026-69243: aio-libs aiohttp · HTTP Request/Response Smuggling
Affects aio-libs aiohttpSource CVE Database V5
Not known to be exploited · CVSS 6.3 Medium : upgrade to 3.14.2 when convenient.
Data as of 1 Nov 2026, 22:58 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 38% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 3.14.2
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 3 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
Public exploit code: GitHub proofs of concept
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), GitHub proofs of concept, the Metasploit, Exploit-DB and nuclei-templates index as of 1 Nov 2026.
What to do
Upgrade aio-libs aiohttp to 3.14.2.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| aio-libsaiohttp | Affected
| Fixed in
|
PyPIaiohttppkg:pypi/aiohttpOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
This vulnerability is fixed in aiohttp version 3.14.2. Users should upgrade to version 3.14.2 or later to remediate this issue. No other official remediation or temporary fixes are indicated. Patch status is confirmed by the vendor advisory stating the fix is included in 3.14.2.
Description
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.
References
- github.com/aio-libs/aiohttp/security/advisories/GHSA-mfx4-hv73-q22v (opens in a new tab)
- github.com/aio-libs/aiohttp/pull/13017 (opens in a new tab)
- github.com/aio-libs/aiohttp/commit/6ae358f0983c3f4d6f67692b2f8e65dc8e091c98 (opens in a new tab)
- github.com/aio-libs/aiohttp/releases/tag/v3.14.2 (opens in a new tab)