# CVE-2026-85595: Traefik before v2.11.55 and v3.0.0 through v3.7.10 Authentication Bypass via digestAuth

> Attackers can bypass digestAuth authentication in Traefik by using an empty secret, allowing unauthorized access to protected routes.

- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/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:** 4 Sep 2026
- **Updated:** 8 Oct 2026
- **Also known as:** GHSA-4v96-rv7j-9wmr, GHSA-5w68-77r2-r64c, MINI-62vx-jwcp-f495, MINI-c6mp-gc5p-9j7x, MINI-j98f-hw2h-w48x

## What is CVE-2026-85595?

CVE-2026-85595 is a critical authentication bypass vulnerability in Traefik Traefik, published on 4 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Traefik versions before v2.11.55 and versions v3.0.0 through v3.7.10 contain an authentication bypass vulnerability in the digestAuth middleware where unknown usernames receive an empty secret instead of rejection. Attackers can compute a valid digest response using the empty secret and arbitrary credentials to bypass authentication on any digestAuth-protected route without a valid username or password.

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2026-85595?

It affects 1 product.


Products: Traefik Traefik.

## How do I fix CVE-2026-85595?

Upgrade to a fixed version.

## Is CVE-2026-85595 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-85595 exists.

Public exploit code:

- CVE-2026-85595 — Traefik digestAuth authentication bypass (unknown username => empty HA1). Lab-verified: v3.7.10 bypass, v3.7.11 401. (github_poc): https://github.com/Boreas37/CVE-2026-85595-PoC
- Traefik < 2.11.55 / 3.0.0 - 3.7.10 - Digest Authentication Bypass (nuclei): http/cves/2026/CVE-2026-85595.yaml

## 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-2026-88007](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)
- [CVE-2025-32431](https://insights.sbomify.com/CVE-2025-32431/): Traefik has a possible vulnerability with the path matchers (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-85595 and fix it if it is affected.

What it is: CVE-2026-85595 is a critical authentication bypass vulnerability in Traefik Traefik, published on 4 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-85595 exists.

Affected product: Traefik Traefik. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-85595/ (Markdown: https://insights.sbomify.com/CVE-2026-85595/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-85595
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-85595
- OSV: https://osv.dev/vulnerability/CVE-2026-85595

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-85595/
Summaries are generated and may contain mistakes; the official description above is the record.