Vulnerability in io.netty:netty-transport-sctp (CVE-2026-59902)
Summary
Vulnerability in io.netty:netty-transport-sctp (CVE-2026-59902). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 4.1.137.Final or later.
Original description
The description as published by the source.
Summary
SctpMessageCompletionHandler does not limit the total size of buffered fragments, allowing an unauthenticated attacker to cause an OutOfMemoryError by sending large SCTP fragments.
Details
io.netty.handler.codec.sctp.SctpMessageCompletionHandler buffers fragments for incomplete SCTP messages. The fix for CVE-2026-46340 fixed unbounded memory growth by introducing limits on the number of concurrent incomplete messages (maxIncompleteSctpMessages) and the number of fragments per message (maxFragments).
While the count of fragments is now bounded, the handler still does not enforce a maximum size in bytes.
With the default limits of 128 messages and 128 fragments, and a typical max SCTP chunk size of 64KB, an attacker can consume up to ~1GB per connection. By opening a small number of concurrent connections, an attacker can easily exhaust the server's memory, causing an OutOfMemoryError.
Impact
Memory Exhaustion. Any application using Netty's SCTP transport with SctpMessageCompletionHandler is impacted.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-59902 has been found in io.netty:netty-transport-sctp.
Risk of unauthorized operations or information disclosure. CVSS score: 7.5/10.
What to do: upgrade io.netty:netty-transport-sctp to 4.1.137.Final or later.
If unsure, ask your IT team or search "io.netty:netty-transport-sctp CVE-2026-59902" on the vendor's site.
CVE-2026-59902 (io.netty:netty-transport-sctp) — CWE-400 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 4.1.137.Final — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-400) exists in io.netty:netty-transport-sctp.
Check the vendor advisory for the affected versions of io.netty:netty-transport-sctp.
Severity: High (CVSS 7.5/10). Risk of unauthorized operations or information disclosure.
Update to 4.1.137.Final.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで io.netty:netty-transport-sctp を使っているサービスとバージョンを洗い出す。
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2Apply patch patch
Upgrade io.netty:netty-transport-sctp to 4.1.137.Finalステージング環境で 4.1.137.Final に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
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3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。