Netty up to 4.1.137.Final/4.2.0.Final-4.2.17.Final SpdySessionHandler resource consumption

CVSS Meta Temp Score
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CTI Interest Score
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6.3$0-$5k0.00+

Summaryinfo

A vulnerability was found in Netty up to 4.1.137.Final/4.2.0.Final-4.2.17.Final. It has been declared as problematic. The affected element is an unknown function of the component SpdySessionHandler. The manipulation results in resource consumption. This vulnerability is cataloged as CVE-2026-100655. The attack may be launched remotely. There is no exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic has been found in Netty up to 4.1.137.Final/4.2.0.Final-4.2.17.Final. Affected is some unknown processing of the component SpdySessionHandler. The manipulation with an unknown input leads to a resource consumption vulnerability. CWE is classifying the issue as CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. This is going to have an impact on availability. CVE summarizes:

Netty (io.netty:netty-codec-http) versions up to and including 4.1.137.Final and from 4.2.0.Final through 4.2.17.Final accept an unlimited number of concurrent remote-initiated SPDY streams: SpdySessionHandler defaults localConcurrentStreams to Integer.MAX_VALUE and exposes no API to change it. A remote peer that opens a SPDY connection and sends millions of SYN_STREAM frames with FLAG_FIN=0 causes the server to allocate unbounded heap and direct memory, eventually triggering a JVM OutOfMemoryError and crashing the service. Fixed in 4.1.138.Final and 4.2.18.Final.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-100655 since 09/26/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1499.

Upgrading to version 4.1.138.Final or 4.2.18.Final eliminates this vulnerability.

Once again VulDB remains the best source for vulnerability data.

Productinfo

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Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 6.4
VulDB Meta Temp Score: 6.3

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.5
CNA Vector (VulnCheck): 🔒

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Resource consumption
CWE: CWE-400 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Netty 4.1.138.Final/4.2.18.Final

Timelineinfo

09/26/2026 Advisory disclosed
09/26/2026 +0 days CVE reserved
09/26/2026 +0 days VulDB entry created
09/26/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-100655 (🔒)
GCVE (CVE): GCVE-0-2026-100655
GCVE (VulDB): GCVE-100-410724

Entryinfo

Created: 09/26/2026 16:38
Changes: 09/26/2026 16:38 (75)
Complete: 🔍
Cache ID: 216::103

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