Vulnerability in quic (CVE-2026-49457)
Summary
Vulnerability in quic (CVE-2026-49457). Confidential information can be exposed externally. Exploitable via verify. Mitigation: upgrade to 1.4.4 or later.
Original description
The description as published by the source.
Impact
The QUIC client did not authenticate the server during the TLS 1.3 handshake. The CertificateVerify signature was not checked, the certificate chain was not validated, and the hostname was not compared against the certificate, so verify was effectively a no-op on the client. A man-in-the-middle on the network path could present any certificate and impersonate any server, defeating the confidentiality and integrity of the connection. HTTP/3 uses the same client and was equally affected. Handshakes authenticated by a PSK (session resumption) are not affected, because the peer is authenticated by the PSK binder and no certificate is sent.
Patches
Fixed in 1.4.4. The client now verifies the CertificateVerify signature, validates the certificate chain against the trust store (cacerts option, the operating system store by default), and checks the hostname. Client verify now defaults to on; set verify => false to accept any certificate (for example a self-signed test server).
Workarounds
None before 1.4.4. verify => true had no effect, and inspecting the certificate after connecting does not help because without the signature check the peer is never proven to own the certificate it presents.
Credit
Reported by benmmurphy.
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-2026-49457 has been found in quic.
Attackers can target a specific entry point like verify over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 9.1/10.
What to do: upgrade quic to 1.4.4 or later.
If unsure, ask your IT team or search "quic CVE-2026-49457" on the vendor's site.
CVE-2026-49457 (quic) — CWE-295 / CVSS v3 9.1
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: verify / cacerts
Patched: 1.4.4 — apply immediately
Workaround: None before 1.4.4.
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-295) exists in quic. Attackers reach the vulnerable code path via verify without authentication.
Check the vendor advisory for the affected versions of quic. Attack surface: verify / cacerts.
Severity: Critical (CVSS 9.1/10). Confidential information can be exposed externally.
Update to 1.4.4.
Workaround: None before 1.4.4.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'quic' . 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 'quic' . | 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
quicを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply temporary workaround mitigate
None before 1.4.4.パッチが適用されるまでの応急処置として、None before 1.4.4. を実施。回避策の副作用 (機能低下) を確認した上で。
-
3Apply patch patch
Upgrade quic to 1.4.4ステージング環境で 1.4.4 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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4Post-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
- package github.com
- web security-advisories@github.com
- web github.com