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CVE-2026-56819
high
CVSS 7.5
Vulnerability in io.netty:netty-codec-http2 (CVE-2026-56819)
Summary
vulnerability in io.netty:netty-codec-http2 (CVE-2026-56819). Risk of unauthorized operations or information disclosure. Exploitable via ``ByteBuf``. Mitigation: upgrade to `4.1.136.Final` or later.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2026-56819** has been found in io.netty:netty-codec-http2.
Attackers can target a specific entry point like ``ByteBuf`` over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 7.5/10.
What to do: upgrade io.netty:netty-codec-http2 to **4.1.136.Final** or later.
If unsure, ask your IT team or search "io.netty:netty-codec-http2 CVE-2026-56819" on the vendor's site.
CVE-2026-56819 (io.netty:netty-codec-http2) — CWE-400 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: `ByteBuf` / `DATA` / `DelegatingDecompressorFrameListener` / `OutOfMemoryError`
Patched: `4.1.136.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.
❓ What is the problem
**A vulnerability** (CWE-400) exists in io.netty:netty-codec-http2. Attackers reach the vulnerable code path via ``ByteBuf`` without authentication.
📍 Affected scope
io.netty:netty-codec-http2 — . Attack surface: `ByteBuf` / `DATA` / `DelegatingDecompressorFrameListener` / `OutOfMemoryError`.
🔥 Severity
Severity: High (CVSS 7.5/10). Risk of unauthorized operations or information disclosure
🔧 How to fix
Update to **4.1.136.Final**.
🛡️ Workaround
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
🔍 Detection
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run `grep -r 'io.netty:netty-codec-http2' .` against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response Actions (7 steps)
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'io.netty:netty-codec-http2' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で `io.netty:netty-codec-http2` を grep し、稼働しているサービス・バージョンを把握する。
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6Apply patch patch
Upgrade io.netty:netty-codec-http2 to 4.1.136.Finalステージング環境で 4.1.136.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と、Step 3 で見つけた異常検知の続報チェックを含めること。
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7Post-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 Step 3 と同じログクエリでアラート再発が無いか継続監視。
Affected packages
maven
io.netty:netty-codec-http2
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.1.136.Final"}]}]
References
- web https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b
- web https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6
- web https://github.com/netty/netty/releases/tag/netty-4.1.136.Final
- web https://github.com/netty/netty/releases/tag/netty-4.2.16.Final
- web https://github.com/netty/netty/security/advisories/GHSA-93wv-jw9v-4972
- web https://nvd.nist.gov/vuln/detail/CVE-2026-56819
- web https://github.com/advisories/GHSA-93wv-jw9v-4972