CVE-2026-23944 is a critical missing authentication flaw (CVSS 9.8) in Arcane, a Docker management interface, in versions up to 1.13.1. Requests for remote environments were proxied before login was checked, with the manager's agent token attached. Version 1.13.2 fixes it. Upgrade now and keep the manager off public networks.
What's affected
Arcane 1.13.1 and earlier, patched in 1.13.2 per the GitHub advisory. The flaw affects setups that use remote environments, where the manager talks to agents on other hosts.
How to check if you're exposed
Find the image tag or binary version:
docker ps --format "table {{.Names}}\t{{.Image}}"
If it is below 1.13.2, and the manager is reachable by anyone who should not have access, treat it as exposed. Check whether you have any remote environments configured, and whether your reverse proxy or firewall limits who can reach the manager port.
What to do now
- Upgrade Arcane to 1.13.2 or later.
- Put the manager behind a VPN, SSO proxy or IP allowlist. A Docker control plane should not be on the open internet.
- Review the remote agents. The advisory says the issue allows access to operations such as listing containers and streaming logs, so check agent logs for requests you do not recognize.
- Rotate agent tokens if you have any reason to think the manager was reachable from untrusted networks.
Why it matters
The class is CWE-306, missing authentication for a critical function. The advisory explains the cause: the environment proxy middleware ran before authentication, and when the environment was not local, it forwarded the request with the manager's own agent token. The credential belonged to the manager, but any caller got to use it.
Order of middleware is a design detail with security weight. Anything that attaches a privileged credential should only run after the caller has been authenticated. The record does not list this CVE as known exploited.
Reading the severity score
The record gives a CVSS base score of 9.8, published 2026-01-19. In the vector, the attacker works over the network, needs no account, and the attack is low in complexity. User interaction is not needed. Impact on confidentiality is high, on integrity high and on availability high.
A base score describes the flaw in general, not your risk. Weigh it against how exposed your instance is and what it can reach. The Gold page for the CVE keeps the score, weakness and references together.
Hardening beyond the patch
A container management interface is a control plane for every host it reaches. Do not expose it directly. Use an authenticating reverse proxy or VPN, set strong credentials, and give agents the minimum permissions they need. Rotate the tokens that connect the manager to agents on a schedule, and keep audit logs of manager and agent requests. If you manage many hosts, test upgrades of the manager on a small environment first.
Find it across your own code
To see which of your packages are affected, the free in-browser dependency scan at gold.safeguard.sh/scan takes a manifest and lists known vulnerabilities. Reachability analysis then helps you judge whether your code calls the vulnerable path, so you can order the work.
Quick check
Does this affect a single local Docker host?
The advisory describes the flaw in the proxying of requests for remote environments. A setup with only the local environment is less exposed, but upgrading is still the right step.
Sources
Last reviewed: 19 October 2026.
