CVE-2026-128129: aio-libs aiohttp · Unthrottled Resource Allocation
Affects aio-libs aiohttpSource CVE Database V5
Not known to be exploited · CVSS 8.2 High : upgrade to 3.14.4 soon.
Data as of 13 Nov 2026, 20:48 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 4.0 | 8.2 |
|---|
- Patch
- Available – fixed in 3.14.4
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 13 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
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), the Metasploit, Exploit-DB and nuclei-templates index as of 13 Nov 2026.
What to do
Upgrade aio-libs aiohttp to 3.14.4.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| aio-libsaiohttp | Affected
| Fixed in
|
AI-suggested
Upgrade aiohttp to version 3.14.4 or later, where this vulnerability is fixed. No other mitigation is required as the fix is available and official.
Description
CVE-2026-128129 is a high-severity vulnerability in aiohttp, an asynchronous HTTP client/server framework for Python. Versions prior to 3.14.4 buffer all additional connection data received during an HTTP upgrade request, such as a WebSocket handshake, without any size limit or flow control. This allows a remote attacker to stream data behind an upgrade request to a handler that does not promptly accept or reject the upgrade, causing unbounded memory consumption. The issue is fixed in version 3.14.4.
References
- github.com/aio-libs/aiohttp/security/advisories/GHSA-pw86-h8fm-j323 (opens in a new tab)
- github.com/aio-libs/aiohttp/pull/13501 (opens in a new tab)
- github.com/aio-libs/aiohttp/pull/13511 (opens in a new tab)
- github.com/aio-libs/aiohttp/commit/3d850ee9b92573c7e913821cbcb96005beb3f4df (opens in a new tab)
- github.com/aio-libs/aiohttp/commit/c207cadb257e0959b192ffca0548eca8c71eb96a (opens in a new tab)
- github.com/aio-libs/aiohttp/releases/tag/v3.14.4 (opens in a new tab)