vulnerability / NVI-00018418 / Revision 1
Portainer Has an Arbitrary File Read via Git Symlink Injection in Stack Auto-Update
GitHub lists this reviewed advisory for github.com/portainer/portainer, github.com/portainer/portainer, github.com/portainer/portainer. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
9.9 high
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
github.com/portainer/portainer
source listed>= 2.33.0, < 2.33.8
## Summary 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 — including `docker-compose.yml`, which Portainer treats as the stack entry point — 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 (for example `/etc/passwd` or a mounted Kubernetes service account token) 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. The issue is amplified by Git-stack auto-update: an attacker can create a stack from a legitimate repository, pass initi
github.com/portainer/portainer
source listed>= 2.39.0, < 2.39.2
## Summary 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 — including `docker-compose.yml`, which Portainer treats as the stack entry point — 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 (for example `/etc/passwd` or a mounted Kubernetes service account token) 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. The issue is amplified by Git-stack auto-update: an attacker can create a stack from a legitimate repository, pass initi
github.com/portainer/portainer
source listed>= 2.40.0, < 2.41.0
## Summary 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 — including `docker-compose.yml`, which Portainer treats as the stack entry point — 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 (for example `/etc/passwd` or a mounted Kubernetes service account token) 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. The issue is amplified by Git-stack auto-update: an attacker can create a stack from a legitimate repository, pass initi
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-rpgq-m5fp-32wr ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.