Information Disclosure in io.netty:netty-codec-classes-quic (CVE-2026-50009)
Summary
Vulnerability in io.netty:netty-codec-classes-quic (CVE-2026-50009). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 4.2.15.Final or later.
Original description
The description as published by the source.
Netty is a network application framework for development of protocol servers and clients. Prior to version 4.2.15.Final, Netty QUIC exposes the stateless reset token on the network path when using the default HMAC-based connection-ID and stateless-reset-token generators. The reset token for the server's current source connection ID can be derived from bytes that appear as the connection ID in QUIC headers after a source-CID rotation. An on-path attacker observing the headers can use the token to perform a Denial of Service by sending a spoofed Stateless Reset packet. Version 4.2.15.Final patches the issue.
Source: NIST National Vulnerability Database 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-2026-50009 has been found in io.netty:netty-codec-classes-quic.
Risk of unauthorized operations or information disclosure. CVSS score: 4.8/10.
What to do: upgrade io.netty:netty-codec-classes-quic to 4.2.15.Final or later.
If unsure, ask your IT team or search "io.netty:netty-codec-classes-quic CVE-2026-50009" on the vendor's site.
CVE-2026-50009 (io.netty:netty-codec-classes-quic) — CWE-200 / CVSS v3 4.8
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 4.2.15.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.
Information disclosure (CWE-200) exists in io.netty:netty-codec-classes-quic.
Check the vendor advisory for the affected versions of io.netty:netty-codec-classes-quic.
Severity: Medium (CVSS 4.8/10). Risk of unauthorized operations or information disclosure.
Update to 4.2.15.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-codec-classes-quic 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-codec-classes-quic to 4.2.15.Finalステージング環境で 4.2.15.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。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-50009 netty
- Ubuntu UBUNTU-CVE-2026-50009 netty
References
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- web github.com
- web github.com