9.8Critical
Traefik Traefik
CVE-2026-85595
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.
What this means for your business
- It affects Traefik. It matters if your company, or a supplier that handles your data, runs it.
- Code showing how to exploit it has been published, but real attacks have not been confirmed.
- An attacker can use it remotely, over a network, without a login, and without anyone at your company clicking anything.
- FIRST's prediction model gives it a 0.4% chance of attack attempts being seen in the next 30 days, ranking above 34% of all known flaws.
What to do
- 1Check whether your company or your suppliers run Traefik, and which version. The affected versions are listed further down this page.
- 2If you do, apply the vendor's fix. A patch or vendor advisory has been published.
Not sure if your company is exposed?
Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.
Scoring
- CVSS
- 9.8 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H- CVSS v4
- 9.3
- Weakness
- CWE-287
- Assigned by
- disclosure@vulncheck.com
Dates
- Published
- 2026-09-04
- Last modified
- 2026-09-16
- Sources
- NVD
Affected products
- Traefik Traefik- 2.11.55, 3.0.0 - 3.7.11
As listed in the NVD configuration data. Not a statement about your estate.