Vulnerability in io.netty:netty-codec-http2 (CVE-2026-50560)
Summary
Vulnerability in io.netty:netty-codec-http2 (CVE-2026-50560). Risk of unauthorized operations or information disclosure. Exploitable via SETTINGS_MAX_HEADER_LIST_SIZE. Mitigation: upgrade to 4.1.135.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 versions 4.1.135.Final and 4.2.15.Final, Netty HTTP/2 max header size handling produces an attack similar to HTTP/2 Rapid Reset. There is a setting in the http2 specification called SETTINGS_MAX_HEADER_LIST_SIZE. When a client sends that setting to Netty, it appears that Netty will behave as follows: read the request; proxy the request to the origin; attempt to produce a response; and create an exception while writing the headers for the response. Functionally, this should be similar to the http2 reset attack, but with a different on-the-wire signature. Versions 4.1.135.Final and 4.2.15.Final patch 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-2026-50560 has been found in io.netty:netty-codec-http2.
Attackers can target a specific entry point like SETTINGS_MAX_HEADER_LIST_SIZE over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 5.3/10.
What to do: upgrade io.netty:netty-codec-http2 to 4.1.135.Final or later.
If unsure, ask your IT team or search "io.netty:netty-codec-http2 CVE-2026-50560" on the vendor's site.
CVE-2026-50560 (io.netty:netty-codec-http2) — CWE-770 / CVSS v3 5.3
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: SETTINGS_MAX_HEADER_LIST_SIZE
Patched: 4.1.135.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-http2. Attackers reach the vulnerable code path via SETTINGS_MAX_HEADER_LIST_SIZE without authentication.
Check the vendor advisory for the affected versions of io.netty:netty-codec-http2. Attack surface: SETTINGS_MAX_HEADER_LIST_SIZE.
Severity: Medium (CVSS 5.3/10). Risk of unauthorized operations or information disclosure.
Update to 4.1.135.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-http2 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-http2 to 4.1.135.Finalステージング環境で 4.1.135.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-2026-50560 netty
- Ubuntu UBUNTU-CVE-2026-50560 netty
References
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- web github.com
- web github.com
- web rfc-editor.org
- web github.com