# CVE-2026-71324: Traefik: Cross-user response poisoning via proxied CONNECT on Traefik's shared backend keep-alive pool > An unauthenticated attacker can poison responses to other clients via HTTP CONNECT desynchronization in Traefik's shared connection pool, leaking private data. - **Severity:** High 7.0 (`CVSS:4.0/AV:N/AC:L/AT:P/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:** 6 Aug 2026 - **Updated:** 7 Aug 2026 - **Also known as:** GHSA-3ccp-42pg-hgv6, GO-2026-6201, MINI-mf3v-fcvh-jhrx, MINI-rgh9-m5r7-xq4g, MINI-w45r-wpqg-9f4j ## What is CVE-2026-71324? CVE-2026-71324 is a high-severity vulnerability in Traefik Traefik, published on 6 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description Traefik is an open source HTTP reverse proxy and load balancer. Prior to 2.11.53, 3.6.24, and 3.7.9, Traefik's default HTTP reverse proxy forwards a plain HTTP/2 or HTTP/3 CONNECT request and its body to an HTTP/1.1 upstream through a shared net/http.Transport. When the upstream answers the CONNECT with a keep-alive non-2xx response and does not drain the body, Traefik returns the desynchronized backend socket to its shared pool and reuses it for other clients. An unauthenticated attacker can use this behavior to make a different client read the attacker's smuggled response, which can include authenticated or private content from another request. The ForwardAuth middleware with forwardBody true and preserveRequestMethod true can re-issue a CONNECT with the buffered body attached, exposing the auth-client pool to the same desynchronization. This issue is fixed in 2.11.53, 3.6.24, and 3.7.9. Weakness: CWE-444 (Inconsistent Interpretation of HTTP Requests) ## Which versions are affected by CVE-2026-71324? 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 | 3.6.24, 3.7.9 | | `github.com/traefik/traefik/v3` | Go | All versions | 3.6.24 | | `github.com/traefik/traefik/v3` | Go | All versions | 3.6.24 | | `github.com/traefik/traefik/v3` | Go | From 3.7.0 | 3.7.9 | | `github.com/traefik/traefik/v3` | Go | From 3.7.0 | 3.7.9 | | `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 | 2.11.53 | | `github.com/traefik/traefik/v2` | Go | All versions | 2.11.53 | | `github.com/traefik/traefik/v2` | Go | All versions | 2.11.53 | Products: Traefik Traefik. ## How do I fix CVE-2026-71324? Upgrade github.com/traefik/traefik/v3 to a fixed version for your release line: 3.6.24 or 3.7.9. ## Is CVE-2026-71324 being exploited? There is no known exploitation of CVE-2026-71324 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-2026-71324 and fix it if it is affected. What it is: CVE-2026-71324 is a high-severity vulnerability in Traefik Traefik, published on 6 Aug 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-2026-71324 in the wild and no public exploit code. Affected packages and fixed versions: - github.com/traefik/traefik/v3 (Go): affected all versions; fixed in 3.6.24, 3.7.9 - github.com/traefik/traefik/v3 (Go): affected all versions; fixed in 3.6.24 - github.com/traefik/traefik/v3 (Go): affected all versions; fixed in 3.6.24 - github.com/traefik/traefik/v3 (Go): affected from 3.7.0; fixed in 3.7.9 - github.com/traefik/traefik/v3 (Go): affected from 3.7.0; fixed in 3.7.9 - 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 2.11.53 - github.com/traefik/traefik/v2 (Go): affected all versions; fixed in 2.11.53 - github.com/traefik/traefik/v2 (Go): affected all versions; fixed in 2.11.53 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-2026-71324/ (Markdown: https://insights.sbomify.com/CVE-2026-71324/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-71324 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-71324 - OSV: https://osv.dev/vulnerability/CVE-2026-71324 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-71324/ Summaries are generated and may contain mistakes; the official description above is the record.