CVE-2026-86775 knowns before 0.30.0 Path Traversal via Document API
Remote attackers can read, write, or delete arbitrary files on the host via path traversal in the Document API, potentially leading to code execution.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-86775?
CVE-2026-86775 is a high-severity path traversal vulnerability in knowns-dev knowns, published on 9 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
knowns (npm package) versions <= 0.29.1 contain a path traversal vulnerability in the Document API. The HTTP handler in internal/server/routes/docs.go normalizes the user-supplied document path with cleanDocPath(), which strips leading/trailing slashes and the .md suffix but does not neutralize ../ traversal sequences, and internal/storage/doc_store.go then builds the target path with filepath.Join(ds.docsDir(), filepath.FromSlash(doc.Path)+".md") without verifying that the resolved path remains inside the documents directory. In the default deployment, where the Management API is unauthenticated and bound to all interfaces, a remote unauthenticated attacker can supply a traversal payload (for example {"path": "../../../../tmp/knowns_pwn_marker"} to POST /api/docs, or an encoded path to GET /api/docs/...) to read, create, overwrite, or delete arbitrary files with a .md extension anywhere on the host filesystem and to create arbitrary directories via os.MkdirAll. This can expose sensitive data stored in other projects' documentation, corrupt or destroy files, and provide an arbitrary-write primitive that may be chained toward code execution. The issue is fixed in version 0.30.0.
Weakness: CWE-22
Which versions are affected by CVE-2026-86775?
How do I fix CVE-2026-86775?
No fix has been published for CVE-2026-86775 yet. Limit exposure of the affected software until one is available.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-86775 being exploited?
There is no known exploitation of CVE-2026-86775 in the wild and no public exploit code.
Sources
Also known as GHSA-3h35-4jq7-hv45, GHSA-h5q7-w9w4-9hcf.