Io.netty:netty transport sctp: Netty: Memory Exhaustion in SctpMessageCompletionHandler (CVE-2026-59902)
The SctpMessageCompletionHandler in io.netty:netty-transport-sctp does not enforce a maximum size limit on buffered SCTP message fragments. This allows an unauthenticated attacker to cause memory exhaustion by sending large SCTP fragments, potentially leading to an OutOfMemoryError and denial of service. Although limits on the number of incomplete messages and fragments per message were introduced in a prior fix, the total buffered size remains unbounded. This vulnerability affects any application using Netty's SCTP transport with this handler.
AI Analysis
Technical Summary
The vulnerability in io.netty.handler.codec.sctp.SctpMessageCompletionHandler arises because it buffers fragments of incomplete SCTP messages without limiting the total size in bytes. While previous fixes limited the number of concurrent incomplete messages and fragments per message, the absence of a maximum byte size limit allows an attacker to consume approximately 1GB of memory per connection by sending large SCTP fragments. Opening a few concurrent connections can exhaust server memory, causing an OutOfMemoryError. This is a denial-of-service vulnerability classified under CWE-400 (Uncontrolled Resource Consumption).
Potential Impact
An unauthenticated attacker can cause memory exhaustion on servers using Netty's SCTP transport by sending large SCTP fragments, leading to an OutOfMemoryError and potential denial of service. There is no impact on confidentiality or integrity, but availability is severely affected.
Mitigation Recommendations
A patch is available for this vulnerability. Users should apply the official fix provided by the Netty project to enforce limits on the total size of buffered SCTP fragments. Until patched, consider limiting exposure of SCTP services to untrusted networks to reduce attack surface.
Io.netty:netty transport sctp: Netty: Memory Exhaustion in SctpMessageCompletionHandler (CVE-2026-59902)
Description
The SctpMessageCompletionHandler in io.netty:netty-transport-sctp does not enforce a maximum size limit on buffered SCTP message fragments. This allows an unauthenticated attacker to cause memory exhaustion by sending large SCTP fragments, potentially leading to an OutOfMemoryError and denial of service. Although limits on the number of incomplete messages and fragments per message were introduced in a prior fix, the total buffered size remains unbounded. This vulnerability affects any application using Netty's SCTP transport with this handler.
CVSS v3.1
Score 7.5high
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in io.netty.handler.codec.sctp.SctpMessageCompletionHandler arises because it buffers fragments of incomplete SCTP messages without limiting the total size in bytes. While previous fixes limited the number of concurrent incomplete messages and fragments per message, the absence of a maximum byte size limit allows an attacker to consume approximately 1GB of memory per connection by sending large SCTP fragments. Opening a few concurrent connections can exhaust server memory, causing an OutOfMemoryError. This is a denial-of-service vulnerability classified under CWE-400 (Uncontrolled Resource Consumption).
Potential Impact
An unauthenticated attacker can cause memory exhaustion on servers using Netty's SCTP transport by sending large SCTP fragments, leading to an OutOfMemoryError and potential denial of service. There is no impact on confidentiality or integrity, but availability is severely affected.
Mitigation Recommendations
A patch is available for this vulnerability. Users should apply the official fix provided by the Netty project to enforce limits on the total size of buffered SCTP fragments. Until patched, consider limiting exposure of SCTP services to untrusted networks to reduce attack surface.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-2qj4-mmr9-4v2f
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-59902"]
- Ecosystems
- ["Maven"]
- Database Specific Severity
- HIGH
- Cvss Version
- 3.1
Threat ID: 6a838c4dbf8831d539b4cc35
Added to database: 08/17/2026, 22:33:49 UTC
Last enriched: 08/17/2026, 22:41:36 UTC
Last updated: 08/18/2026, 00:42:01 UTC
Views: 8
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