Vulnerability in github.com/apple/swift-nio-http2 (CVE-2026-28898)
Summary
Vulnerability in github.com/apple/swift-nio-http2 (CVE-2026-28898). Risk of unauthorized operations or information disclosure. Exploitable via HTTP2FramePayloadToHTTP1ServerCodec. Mitigation: upgrade to 1.44.0 or later.
Original description
The description as published by the source.
swift-nio-http2's HTTP/2-to-HTTP/1.1 codec (HTTP2FramePayloadToHTTP1ServerCodec / HTTP2ToHTTP1ServerCodec) did not validate pseudo-header values for control characters before placing them into the translated HTTP/1.1 message. A remote attacker could send an HTTP/2 request containing CR (\r), LF (\n), or NUL (\0) bytes in pseudo-header values such as :path, and when the server translated this to HTTP/1.1 — for example in a reverse-proxy configuration — the resulting output could contain injected headers or entirely smuggled requests.
This is an HTTP/2-to-HTTP/1.1 request smuggling vulnerability. HTTP/2's binary framing means that CRLF bytes are never parsed as line terminators at the HTTP/2 layer, so they pass through transparently to the HTTP/1.1 output. Any swift-nio-http2 server that translates HTTP/2 requests to HTTP/1.1 and forwards them to a backend is affected. Server-side Swift frameworks such as Vapor that use this codec in a reverse-proxy pattern are directly affected.
This vulnerability is related to https://github.com/advisories/GHSA-7fj7-39wj-c64f in swift-nio, which addressed CRLF injection in HTTP/1.1 header values but did not cover pseudo-header values in the HTTP/2 layer.
This vulnerability is also related to https://github.com/advisories/GHSA-cq87-8r7h-962v in swift-nio, which addressed CRLF injection in HTTP/1.1 version, method and path.
swift-nio-http2 1.44.0 adds validation of all pseudo-header values (:path, :authority, :scheme, :method, and :st…
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-2026-28898 has been found in github.com/apple/swift-nio-http2.
Attackers can target a specific entry point like HTTP2FramePayloadToHTTP1ServerCodec over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 5.3/10.
What to do: upgrade github.com/apple/swift-nio-http2 to 1.44.0 or later.
If unsure, ask your IT team or search "github.com/apple/swift-nio-http2 CVE-2026-28898" on the vendor's site.
CVE-2026-28898 (github.com/apple/swift-nio-http2) — CWE-116 / CVSS v3 5.3
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: HTTP2FramePayloadToHTTP1ServerCodec / HTTP2ToHTTP1ServerCodec
Patched: 1.44.0 — 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-116) exists in github.com/apple/swift-nio-http2. Attackers reach the vulnerable code path via HTTP2FramePayloadToHTTP1ServerCodec without authentication.
Check the vendor advisory for the affected versions of github.com/apple/swift-nio-http2. Attack surface: HTTP2FramePayloadToHTTP1ServerCodec / HTTP2ToHTTP1ServerCodec.
Severity: Medium (CVSS 5.3/10). Risk of unauthorized operations or information disclosure.
Update to 1.44.0.
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. Run grep -r 'github.com/apple/swift-nio-http2' . against your dependency files (package-lock.json, requirements.txt, go.sum) 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
grep -r 'github.com/apple/swift-nio-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
github.com/apple/swift-nio-http2を grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade github.com/apple/swift-nio-http2 to 1.44.0ステージング環境で 1.44.0 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
References
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com
- web github.com