CVE-2026-44884 Portainer: Missing authorization on custom template file endpoint exposes template content
Authenticated users can read any custom template file, potentially exposing sensitive credentials, due to missing authorization checks.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-44884?
CVE-2026-44884 is a medium-severity missing authorization vulnerability in portainer, published on 28 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Portainer Community Edition is a lightweight service delivery platform for containerized applications that can be used to manage Docker, Swarm, Kubernetes and ACI environments. From 2.33.0 to before 2.33.8 and 2.39.1, a missing authorization vulnerability in the Custom Template file endpoint (GET /api/custom_templates/{id}/file) allows any authenticated user to read the file content of any custom template by enumerating sequential integer IDs, bypassing Resource Control access restrictions. Template files may contain environment-specific values such as connection strings, API tokens, or registry credentials that administrators would not expect standard users to read. This vulnerability is fixed in 2.33.8 and 2.39.1.
Weakness: CWE-862
Which versions are affected by CVE-2026-44884?
5 open source packages ship an affected version, including github.com/portainer/portainer. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/portainer/portainer Go | All versions | None |
github.com/portainer/portainer Go | From 2.33.0 | 2.33.8 |
github.com/portainer/portainer Go | From 2.33.0 | 2.33.8 |
github.com/portainer/portainer Go | From 2.39.0 | 2.39.1 |
github.com/portainer/portainer Go | From 2.39.0 | 2.39.1 |
Products include Portainer Portainer.
How do I fix CVE-2026-44884?
Upgrade github.com/portainer/portainer to a fixed version for your release line: 2.33.8 or 2.39.1.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-44884 being exploited?
There is no known exploitation of CVE-2026-44884 in the wild and no public exploit code.
Other vulnerabilities in portainer
Sources
Also known as GHSA-cqpq-2fgr-8mvc, GO-2026-5333.