Vulnerability in io.netty:netty-codec-http3 (CVE-2026-42582)
Summary
Vulnerability in io.netty:netty-codec-http3 (CVE-2026-42582). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 4.2.13.Final or later.
Original description
The description as published by the source.
Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final, when decoding header blocks, the non-Huffman branch of io.netty.handler.codec.http3.QpackDecoder#decodeHuffmanEncodedLiteral may execute new byte[length] for a string literal before verifying that length bytes are actually present in the compressed field section. The wire encoding allows a very large length to be expressed in few bytes. There is no check that length <= in.readableBytes() before new byte[length]. This vulnerability is fixed in 4.2.13.Final.
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
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-2026-42582 has been found in io.netty:netty-codec-http3.
Risk of unauthorized operations or information disclosure. CVSS score: 7.5/10.
What to do: upgrade io.netty:netty-codec-http3 to 4.2.13.Final or later.
If unsure, ask your IT team or search "io.netty:netty-codec-http3 CVE-2026-42582" on the vendor's site.
CVE-2026-42582 (io.netty:netty-codec-http3) — CWE-770 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 4.2.13.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-770) exists in io.netty:netty-codec-http3.
Check the vendor advisory for the affected versions of io.netty:netty-codec-http3.
Severity: High (CVSS 7.5/10). Risk of unauthorized operations or information disclosure.
Update to 4.2.13.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-http3 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-http3 to 4.2.13.Finalステージング環境で 4.2.13.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-2026-42582 netty
- Ubuntu UBUNTU-CVE-2026-42582 netty
References
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- web github.com