# CVE-2026-32595: Traefik: BasicAuth Middleware Timing Attack Allows Username Enumeration > An unauthenticated attacker can enumerate valid usernames in Traefik's BasicAuth middleware by observing timing differences in response times. - **Severity:** Medium 6.3 (`CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:N/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:** 20 Mar 2026 - **Updated:** 20 Mar 2026 - **Also known as:** CLEANSTART-2026-BT02769, GHSA-g3hg-j4jv-cwfr, GO-2026-4792, MINI-5f9h-5q73-m67r, MINI-c5xx-77x5-r6gg, MINI-qv85-6w89-r9mr ## What is CVE-2026-32595? CVE-2026-32595 is a medium-severity vulnerability in Traefik Traefik, published on 20 Mar 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 2.11.40 and below, 3.0.0-beta1 through 3.6.11, and 3.7.0-ea.1 comtain BasicAuth middleware that allows username enumeration via a timing attack. When a submitted username exists, the middleware performs a bcrypt password comparison taking ~166ms. When the username does not exist, the response returns immediately in ~0.6ms. This ~298x timing difference is observable over the network and allows an unauthenticated attacker to reliably distinguish valid from invalid usernames. This issue is patched in versions 2.11.41, 3.6.11 and 3.7.0-ea.2. Weakness: CWE-208 (Observable Timing Discrepancy) ## Which versions are affected by CVE-2026-32595? 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 | 3.6.11, 3.7.0-ea.2 | | `github.com/traefik/traefik/v3` | Go | All versions | 3.6.11 | | `github.com/traefik/traefik/v3` | Go | All versions | 3.6.11 | | `github.com/traefik/traefik/v3` | Go | From 3.7.0-ea.1 | 3.7.0-ea.2 | | `github.com/traefik/traefik/v3` | Go | From 3.7.0-ea.1 | 3.7.0-ea.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 | 2.11.41 | | `github.com/traefik/traefik/v2` | Go | All versions | 2.11.41 | | `github.com/traefik/traefik/v2` | Go | All versions | 2.11.41 | Products: Traefik Traefik. ## How do I fix CVE-2026-32595? Upgrade github.com/traefik/traefik/v3 to a fixed version for your release line: 3.6.11 or 3.7.0-ea.2. ## Is CVE-2026-32595 being exploited? There is no known exploitation of CVE-2026-32595 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-2026-32595 and fix it if it is affected. What it is: CVE-2026-32595 is a medium-severity vulnerability in Traefik Traefik, published on 20 Mar 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-2026-32595 in the wild and no public exploit code. Affected packages and fixed versions: - github.com/traefik/traefik/v3 (Go): affected all versions; fixed in 3.6.11, 3.7.0-ea.2 - github.com/traefik/traefik/v3 (Go): affected all versions; fixed in 3.6.11 - github.com/traefik/traefik/v3 (Go): affected all versions; fixed in 3.6.11 - github.com/traefik/traefik/v3 (Go): affected from 3.7.0-ea.1; fixed in 3.7.0-ea.2 - github.com/traefik/traefik/v3 (Go): affected from 3.7.0-ea.1; fixed in 3.7.0-ea.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 2.11.41 - github.com/traefik/traefik/v2 (Go): affected all versions; fixed in 2.11.41 - github.com/traefik/traefik/v2 (Go): affected all versions; fixed in 2.11.41 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-2026-32595/ (Markdown: https://insights.sbomify.com/CVE-2026-32595/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-32595 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-32595 - OSV: https://osv.dev/vulnerability/CVE-2026-32595 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-32595/ Summaries are generated and may contain mistakes; the official description above is the record.