CVE-2026-26187 lakeFS vulnerable to path traversal in local block adapter allow cross-namespace and sibling directory access
Authenticated attackers can read and write files outside designated storage boundaries via path traversal in the local block adapter.
- 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-2026-26187?
CVE-2026-26187 is a high-severity path traversal vulnerability in treeverse lakeFS, published on 13 Feb 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
lakeFS is an open-source tool that transforms object storage into a Git-like repositories. Prior to 1.77.0, the local block adapter (pkg/block/local/adapter.go) allows authenticated users to read and write files outside their designated storage boundaries. The verifyRelPath function used strings.HasPrefix() to verify that requested paths fall within the configured storage directory. This check was insufficient because it validated only the path prefix without requiring a path separator, allowing access to sibling directories with similar names. Also, the adapter verified that resolved paths stayed within the adapter's base path, but did not verify that object identifiers stayed within their designated storage namespace. This allowed attackers to use path traversal sequences in the object identifier to access files in other namespaces. Fixed in version v1.77.0.
Weakness: CWE-22
Which versions are affected by CVE-2026-26187?
3 open source packages ship an affected version, including github.com/treeverse/lakefs. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/treeverse/lakefs Go | All versions | 1.77.0 |
github.com/treeverse/lakefs Go | All versions | 1.77.0 |
github.com/treeverse/lakefs Go | All versions | 1.77.0 |
Products include Lakefs Lakefs.
How do I fix CVE-2026-26187?
Upgrade github.com/treeverse/lakefs to 1.77.0 or later.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-26187 being exploited?
There is no known exploitation of CVE-2026-26187 in the wild and no public exploit code.
Other vulnerabilities in treeverse lakeFS
Sources
Also known as GHSA-699m-4v95-rmpm, GO-2026-4494.