CVE-2026-44881 Portainer: Arbitrary File Read via Git Symlink Injection in Stack Auto-Update
Authenticated users can read arbitrary files on the host by creating a Git-backed stack with a symlinked entry point.
- 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-2026-44881?
CVE-2026-44881 is a high-severity path traversal 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, 2.39.2, and 2.41.0, Portainer supports deploying stacks from Git repositories. When a Git-backed stack is created or updated, Portainer clones the repository using go-git v5, which translates Git blob entries with mode 0o120000 (symlink) into real OS symlinks on the host filesystem via os.Symlink. The only entry blocked from becoming a symlink is .gitmodules; every other path is created as a symlink without validation. Portainer's GET /api/stacks/{id}/file endpoint then reads the stack entry point with os.ReadFile, which follows OS symlinks transparently. A repository containing docker-compose.yml as a symlink to an arbitrary filesystem path causes the symlink target's contents to be returned verbatim in the HTTP response. Any authenticated user with rights to create or update a Git-backed stack — the default configuration in Portainer CE — can read arbitrary files accessible to the Portainer process. This vulnerability is fixed in 2.33.8, 2.39.2, and 2.41.0.
Which versions are affected by CVE-2026-44881?
7 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 | 2.39.2 |
github.com/portainer/portainer Go | From 2.39.0 | 2.39.2 |
github.com/portainer/portainer Go | From 2.40.0 | 2.41.0 |
1 more packages
github.com/portainer/portainer Go | From 2.40.0 | 2.41.0 |
Products include Portainer Portainer.
How do I fix CVE-2026-44881?
Upgrade github.com/portainer/portainer to a fixed version for your release line: 2.33.8, 2.39.2 or 2.41.0.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-44881 being exploited?
There is no known exploitation of CVE-2026-44881 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Other vulnerabilities in portainer
Sources
Also known as GHSA-rpgq-m5fp-32wr, GO-2026-5633.