CVE-2026-44881
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedPortainer 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidencePortainer CE versions 2.33.0 through 2.33.7, 2.39.0-2.39.1, and 2.40.0-2.40.x contain a symlink traversal vulnerability in the Git-backed stack deployment feature. When cloning Git repositories, Portainer converts Git blob entries with mode 0o120000 (symlinks) into real OS symlinks without proper path validation, except for .gitmodules. The /api/stacks/{id}/file endpoint then reads stack files using os.ReadFile, which transparently follows these symlinks. This allows any authenticated user with stack create/update permissions to read arbitrary files accessible to the Portainer process.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data>= 2.33.0, < 2.33.8>= 2.34.0, < 2.39.2= 2.40.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify installed Portainer versionAccess the Portainer web UI and check the version displayed in the footer, or query the API at GET /api/system/statusAffected if The version falls within 2.33.0-2.33.7, 2.34.0-2.39.1, or 2.40.0-2.41.0 (pre-fix versions)
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Verify if Git-backed stacks existQuery the API at GET /api/stacks to list all stacks, then inspect each stack object for the presence of a 'RepositoryURL' or 'Git' field indicating Git-backed deploymentAffected if Any stack has a non-empty RepositoryURL field pointing to a Git repository, indicating Git-backed stack deployment is in use
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Inspect stack file storage for symlinksOn the Portainer host filesystem, navigate to the stack files directory (typically under /data/stacks or /var/lib/portainer/stacks) and run 'find . -type l -ls' to list all symlinksAffected if Any symlinks exist in stack directories that point outside the expected stack directory, indicating exploitation of the traversal
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Review API access logs for the vulnerable endpointCheck Portainer logs or reverse proxy logs for access to GET /api/stacks/{id}/file endpoints, especially with unusual path patternsAffected if Requests to /api/stacks/{id}/file return contents of files outside the expected stack directory
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Audit users with stack create/update permissionsUse the Portainer UI under Users or Teams to list accounts with permissions to create or update stacks, or query GET /api/users/{id}/permissionsAffected if Any untrusted or compromised accounts have stack create or update permissions, which are required to exploit this vulnerability
A user is affected if running a vulnerable Portainer version AND has Git-backed stacks in use AND possesses stack create/update permissions that could allow symlink-based path traversal attacks.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped2.33.82.39.2
Upgrade Portainer CE to version 2.33.8, 2.39.2, or 2.41.0 or later to resolve the symlink validation vulnerability. Until upgraded, restrict or audit access to users with stack management permissions.
2.41.0 (or 2.33.8/2.39.2 for older branches)
- Backup your existing Portainer data and configuration
- Stop the current Portainer container/service
- Upgrade Portainer to version 2.41.0 or later (or minimum 2.33.8 or 2.39.2 depending on your branch)
- Verify the upgrade completed successfully
- Restart Portainer service
- Confirm the /api/stacks/{id}/file endpoint no longer follows symlinks outside the expected directory
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation1.0 h
- Testing3.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-44881 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-44881 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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