async-http-client: Uncontrolled Resource Consumption
CVE-2026-107227 is a high-severity uncontrolled resource consumption vulnerability in async-http-client from AsyncHttpClient, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected async-http-client versions: >= 3.0.0, < 3.0.14; >= 2.2.0, <= 2.16.1. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.43% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of async-http-client you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| AsyncHttpClient | async-http-client | >= 3.0.0, < 3.0.14; >= 2.2.0, <= 2.16.1 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA (github.com).
Official description
The AsyncHttpClient (AHC) library allows Java applications to easily execute HTTP requests and asynchronously process HTTP responses. From 2.2.0 until 3.0.14, WebSocket permessage-deflate decompression is unbounded when compression is enabled. The inbound pipeline aggregates compressed frames before WebSocketClientCompressionHandler inflates them, so webSocketMaxFrameSize and webSocketMaxBufferSize do not bound decompressed output. A malicious WebSocket peer can send a small compressed message that expands to a very large Netty buffer and exhausts JVM heap. This issue is fixed in version 3.0.14.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Uncontrolled Resource Consumption
The product does not properly control the allocation and maintenance of a limited resource.
How developers prevent this class of flaw
- Ensure that protocols have specific limits of scale placed on them.
- Ensure that all failures in resource allocation place the system into a safe posture.
More Uncontrolled Resource Consumption vulnerabilities (CWE-400)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other vulnerabilities in async-http-client
- 9.4 Critical severity
- 7.6 High severity
- 8.8 High severity
- 7.5 High severity
- 8.7 High severity
- 7.4 High severity
Recent Uncontrolled Resource Consumption vulnerabilities
- 8.7 High severity
- 7.1 High severity
- 8.2 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
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