← Back
CVE-2026-40898
medium
CVSS 5.3
Vulnerability in github.com/quic-go/quic-go (CVE-2026-40898)
Summary
vulnerability in github.com/quic-go/quic-go (CVE-2026-40898). Risk of unauthorized operations or information disclosure. Exploitable via ``http.Header``. Mitigation: upgrade to `0.59.1` or later.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2026-40898** has been found in github.com/quic-go/quic-go.
Attackers can target a specific entry point like ``http.Header`` 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/quic-go/quic-go to **0.59.1** or later.
If unsure, ask your IT team or search "github.com/quic-go/quic-go CVE-2026-40898" on the vendor's site.
CVE-2026-40898 (github.com/quic-go/quic-go) — CWE-770 / CVSS v3 5.3
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: `http.Header` / `http.Request` / `http.Response` / `http3.Server.MaxHeaderBytes`
Patched: `0.59.1` — 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-770) exists in github.com/quic-go/quic-go. Attackers reach the vulnerable code path via ``http.Header`` without authentication.
📍 Affected scope
github.com/quic-go/quic-go — . Attack surface: `http.Header` / `http.Request` / `http.Response` / `http3.Server.MaxHeaderBytes`.
🔥 Severity
Severity: Medium (CVSS 5.3/10). Risk of unauthorized operations or information disclosure
🔧 How to fix
Update to **0.59.1**.
🛡️ 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 'github.com/quic-go/quic-go' .` 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
-
1Identify exposure identify
grep -r 'github.com/quic-go/quic-go' . | 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/quic-go/quic-go` を grep し、稼働しているサービス・バージョンを把握する。
-
6Apply patch patch
Upgrade github.com/quic-go/quic-go to 0.59.1ステージング環境で 0.59.1 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。
-
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
go
github.com/quic-go/quic-go
[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"0.59.1"}]}]
References
- advisory https://github.com/advisories/GHSA-g754-hx8w-x2g6
- advisory https://nvd.nist.gov/vuln/detail/CVE-2026-40898
- package https://github.com/quic-go/quic-go
- web https://github.com/quic-go/quic-go/security/advisories/GHSA-vvgj-x9jq-8cj9
- web https://github.com/quic-go/quic-go/pull/5642
- web https://github.com/quic-go/quic-go/commit/c56e8c79d1627cc1ed6005b421b4b0adadd83665
- web https://github.com/quic-go/quic-go/releases/tag/v0.59.1
- web https://github.com/advisories/GHSA-vvgj-x9jq-8cj9