# CVE-2026-53622: Traefik: HTTP/3 mTLS bypass via exact SNI TLSOptions lookup for wildcard and mixed-case hosts > Attackers can bypass mTLS enforcement on HTTP/3 routers with wildcard or mixed-case hostnames, accessing protected backends without client certificates. - **Severity:** High 7.8 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 23 Jun 2026 - **Updated:** 2 Sep 2026 - **Also known as:** GHSA-9cr8-q42q-g8m7, GO-2026-5287, MINI-94jf-px4q-g9vw, MINI-r565-x5cx-fjgc, MINI-rg63-2xpq-3p2j ## What is CVE-2026-53622? CVE-2026-53622 is a high-severity authentication bypass vulnerability in Traefik Traefik, published on 23 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description Traefik is an HTTP reverse proxy and load balancer. Versions prior to 3.7.3, 3.6.18, and 2.11.51 have a critical vulnerability in Traefik's HTTP/3 (QUIC) TLS configuration selection that allows unauthenticated clients to bypass router-specific mTLS enforcement. When HTTP/3 is enabled on an entrypoint, the TLS handshake selects the applicable TLS configuration through an exact, case-sensitive lookup on the SNI value, which fails to match wildcard host patterns (e.g., *.example.com) or case variants of the configured hostname. Because the handshake falls back to the default TLS configuration — which may not require client certificates — a client can complete the QUIC handshake without presenting a certificate, while the subsequent HTTP routing layer still dispatches the request to a backend protected by a router-specific mTLS policy. The issue affects deployments where HTTP/3 is enabled, a router uses a wildcard Host rule or case-insensitive hostname matching, a router-specific TLSOptions enforces client certificate authentication, and UDP access to the entrypoint is reachable by an attacker. This vulnerability is fixed in versions 3.7.3, 3.6.18, and 2.11.51. Weakness: CWE-289 (Authentication Bypass by Alternate Name), CWE-288 (Authentication Bypass Using an Alternate Path or Channel) ## Which versions are affected by CVE-2026-53622? 11 open source packages ship an affected version, including github.com/traefik/traefik/v3, github.com/traefik/traefik and github.com/traefik/traefik/v2. It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `github.com/traefik/traefik/v3` | Go | All versions | 3.6.18 | | `github.com/traefik/traefik/v3` | Go | All versions | 3.6.18 | | `github.com/traefik/traefik/v3` | Go | All versions | 3.7.3 | | `github.com/traefik/traefik/v3` | Go | From 3.7.0 | 3.7.3 | | `github.com/traefik/traefik/v3` | Go | From 3.7.0 | 3.7.3 | | `github.com/traefik/traefik` | Go | All versions | None | | `github.com/traefik/traefik` | Go | All versions to 1.7.34 | None | | `github.com/traefik/traefik` | Go | All versions to 1.7.34 | None | | `github.com/traefik/traefik/v2` | Go | All versions | 2.11.51 | | `github.com/traefik/traefik/v2` | Go | All versions | 2.11.51 | | `github.com/traefik/traefik/v2` | Go | All versions | 2.11.51 | Products: Traefik Traefik. ## How do I fix CVE-2026-53622? Upgrade github.com/traefik/traefik/v3 to a fixed version for your release line: 3.6.18 or 3.7.3. ## Is CVE-2026-53622 being exploited? There is no known exploitation of CVE-2026-53622 in the wild and no public exploit code. ## Other vulnerabilities in Traefik Traefik - [CVE-2024-45410](https://insights.sbomify.com/CVE-2024-45410/): HTTP client can remove the X-Forwarded headers in Traefik (critical 9.8) - [CVE-2026-88877](https://insights.sbomify.com/CVE-2026-88877/): Traefik v3.7.0 Authentication Bypass via from-to-www-redirect (critical 9.3) - [CVE-2026-85595](https://insights.sbomify.com/CVE-2026-85595/): Traefik before v2.11.55 and v3.0.0 through v3.7.10 Authentication Bypass via digestAuth (critical 9.3) - [CVE-2026-88007](https://insights.sbomify.com/CVE-2026-88007/): Traefik HTTP/3 Backend NTLM Connection Reuse (critical 9.1) - [CVE-2026-88009](https://insights.sbomify.com/CVE-2026-88009/): Traefik: Rootless HTTP/1 request-target routes as "/" but is forwarded verbatim, bypassing path-scoped routing, middleware guards and access logging (high 8.8) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-53622 and fix it if it is affected. What it is: CVE-2026-53622 is a high-severity authentication bypass vulnerability in Traefik Traefik, published on 23 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: There is no known exploitation of CVE-2026-53622 in the wild and no public exploit code. Affected packages and fixed versions: - github.com/traefik/traefik/v3 (Go): affected all versions; fixed in 3.6.18 - github.com/traefik/traefik/v3 (Go): affected all versions; fixed in 3.6.18 - github.com/traefik/traefik/v3 (Go): affected all versions; fixed in 3.7.3 - github.com/traefik/traefik/v3 (Go): affected from 3.7.0; fixed in 3.7.3 - github.com/traefik/traefik/v3 (Go): affected from 3.7.0; fixed in 3.7.3 - github.com/traefik/traefik (Go): affected all versions; no fix listed - github.com/traefik/traefik (Go): affected all versions up to 1.7.34; no fix listed - github.com/traefik/traefik (Go): affected all versions up to 1.7.34; no fix listed - github.com/traefik/traefik/v2 (Go): affected all versions; fixed in 2.11.51 - github.com/traefik/traefik/v2 (Go): affected all versions; fixed in 2.11.51 - github.com/traefik/traefik/v2 (Go): affected all versions; fixed in 2.11.51 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2026-53622/ (Markdown: https://insights.sbomify.com/CVE-2026-53622/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53622 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53622 - OSV: https://osv.dev/vulnerability/CVE-2026-53622 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-53622/ Summaries are generated and may contain mistakes; the official description above is the record.