# CVE-2026-41174: Traefik Kubernetes CRD allows unauthorized cross-namespace middleware binding > Attackers with CRD permissions can bypass cross-namespace isolation to bind unauthorized middleware, requiring an upgrade to patched Traefik versions. - **Severity:** Medium 4.8 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N`) - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Local or same network only - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 30 Apr 2026 - **Updated:** 4 May 2026 - **Also known as:** CLEANSTART-2026-XS53606, GHSA-xhjw-95fp-8vgq, GO-2026-5760, MINI-2x49-ccwm-8gvq, MINI-4c5v-x5w2-g27w, MINI-c5gx-9crm-5778 ## What is CVE-2026-41174? CVE-2026-41174 is a medium-severity missing authorization vulnerability in Traefik Traefik, published on 30 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim. ### Official description Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.43, 3.6.14, and 3.7.0-rc.2, there is a potential vulnerability in Traefik's Kubernetes CRD provider cross-namespace isolation enforcement. When providers.kubernetesCRD.allowCrossNamespace=false, Traefik correctly rejects direct cross-namespace middleware references from IngressRoute objects, but fails to apply the same restriction to middleware references nested inside a Chain middleware's spec.chain.middlewares[]. An actor with permission to create or update Traefik CRDs in their own namespace can exploit this to cause Traefik to resolve and apply middleware objects from another namespace, bypassing the documented isolation boundary. This issue has been patched in versions 2.11.43, 3.6.14, and 3.7.0-rc.2. Weakness: CWE-863 (Incorrect Authorization), CWE-653 (Improper Isolation or Compartmentalization) ## Which versions are affected by CVE-2026-41174? 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 | From 3.0.0-beta1 | 3.6.14, 3.7.0-rc.2 | | `github.com/traefik/traefik/v3` | Go | From 3.0.0-beta1 | 3.6.14 | | `github.com/traefik/traefik/v3` | Go | From 3.0.0-beta1 | 3.6.14 | | `github.com/traefik/traefik/v3` | Go | From 3.7.0-ea.1 | 3.7.0-rc.2 | | `github.com/traefik/traefik/v3` | Go | From 3.7.0-ea.1 | 3.7.0-rc.2 | | `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 | 2.11.43 | | `github.com/traefik/traefik/v2` | Go | All versions | 2.11.43 | | `github.com/traefik/traefik/v2` | Go | All versions | 2.11.43 | Products: Traefik Traefik. ## How do I fix CVE-2026-41174? Upgrade github.com/traefik/traefik/v3 to a fixed version for your release line: 3.6.14 or 3.7.0-rc.2. ## Is CVE-2026-41174 being exploited? There is no known exploitation of CVE-2026-41174 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-2026-41174 and fix it if it is affected. What it is: CVE-2026-41174 is a medium-severity missing authorization vulnerability in Traefik Traefik, published on 30 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim. Exploitation: There is no known exploitation of CVE-2026-41174 in the wild and no public exploit code. Affected packages and fixed versions: - github.com/traefik/traefik/v3 (Go): affected from 3.0.0-beta1; fixed in 3.6.14, 3.7.0-rc.2 - github.com/traefik/traefik/v3 (Go): affected from 3.0.0-beta1; fixed in 3.6.14 - github.com/traefik/traefik/v3 (Go): affected from 3.0.0-beta1; fixed in 3.6.14 - github.com/traefik/traefik/v3 (Go): affected from 3.7.0-ea.1; fixed in 3.7.0-rc.2 - github.com/traefik/traefik/v3 (Go): affected from 3.7.0-ea.1; fixed in 3.7.0-rc.2 - 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 2.11.43 - github.com/traefik/traefik/v2 (Go): affected all versions; fixed in 2.11.43 - github.com/traefik/traefik/v2 (Go): affected all versions; fixed in 2.11.43 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-2026-41174/ (Markdown: https://insights.sbomify.com/CVE-2026-41174/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-41174 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-41174 - OSV: https://osv.dev/vulnerability/CVE-2026-41174 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-41174/ Summaries are generated and may contain mistakes; the official description above is the record.