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… (CVE-2026-100655)
Netty's io.netty:netty-codec-http library versions up to 4.1.137.Final and from 4.2.0.Final through 4.2.17.Final have a vulnerability where the SpdySessionHandler accepts an unlimited number of concurrent SPDY streams. This can lead to unbounded memory allocation when a remote peer sends many SYN_STREAM frames, causing a JVM OutOfMemoryError and service crash. The issue is fixed in versions 4.1.138.Final and 4.2.18.Final.
AI Analysis
Technical Summary
The vulnerability in Netty's HTTP codec component (io.netty:netty-codec-http) affects versions up to 4.1.137.Final and from 4.2.0.Final through 4.2.17.Final. The SpdySessionHandler defaults the localConcurrentStreams parameter to Integer.MAX_VALUE and does not provide an API to limit this value. A remote attacker can exploit this by opening a SPDY connection and sending millions of SYN_STREAM frames without the FLAG_FIN set, causing the server to allocate unlimited heap and direct memory. This leads to a JVM OutOfMemoryError and crashes the service. The vulnerability is addressed in versions 4.1.138.Final and 4.2.18.Final.
Potential Impact
An unauthenticated remote attacker can cause a denial of service by triggering a JVM OutOfMemoryError through unbounded memory allocation, crashing the affected service. There is no impact on confidentiality or integrity reported.
Mitigation Recommendations
Upgrade to Netty versions 4.1.138.Final or later, or 4.2.18.Final or later, where the vulnerability is fixed. No other mitigation or temporary workaround is indicated.
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… (CVE-2026-100655)
Description
Netty's io.netty:netty-codec-http library versions up to 4.1.137.Final and from 4.2.0.Final through 4.2.17.Final have a vulnerability where the SpdySessionHandler accepts an unlimited number of concurrent SPDY streams. This can lead to unbounded memory allocation when a remote peer sends many SYN_STREAM frames, causing a JVM OutOfMemoryError and service crash. The issue is fixed in versions 4.1.138.Final and 4.2.18.Final.
CVSS v3.1
Score 7.5high
Affected software
pkg:maven/io.netty/netty-codec-httpRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in Netty's HTTP codec component (io.netty:netty-codec-http) affects versions up to 4.1.137.Final and from 4.2.0.Final through 4.2.17.Final. The SpdySessionHandler defaults the localConcurrentStreams parameter to Integer.MAX_VALUE and does not provide an API to limit this value. A remote attacker can exploit this by opening a SPDY connection and sending millions of SYN_STREAM frames without the FLAG_FIN set, causing the server to allocate unlimited heap and direct memory. This leads to a JVM OutOfMemoryError and crashes the service. The vulnerability is addressed in versions 4.1.138.Final and 4.2.18.Final.
Potential Impact
An unauthenticated remote attacker can cause a denial of service by triggering a JVM OutOfMemoryError through unbounded memory allocation, crashing the affected service. There is no impact on confidentiality or integrity reported.
Mitigation Recommendations
Upgrade to Netty versions 4.1.138.Final or later, or 4.2.18.Final or later, where the vulnerability is fixed. No other mitigation or temporary workaround is indicated.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-q842-gx74-cj48
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-100655"]
- Database Specific Severity
- MODERATE
- Cvss Version
- 3.1
Threat ID: 6ab89be0f7a7c5410694205a
Added to database: 09/27/2026, 04:30:24 UTC
Last enriched: 09/27/2026, 04:43:37 UTC
Last updated: 09/28/2026, 01:47:40 UTC
Views: 19
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