CVE-2026-86775

knowns before 0.30.0 Path Traversal via Document API

Published Sep 9, 2026 CVSS 4.0 · 8.8 High EPSS < 1% KEV · Not listed

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.

Analysis

Technical impact

This vulnerability exists in versions of the knowns npm package up to 0.29.1. The Document API normalizes input paths but fails to sanitize directory traversal sequences, allowing an attacker who can call the unprotected Management API to read, create, overwrite, or delete any markdown file on the host filesystem. By specifying paths such as …../../../../tmp/marker.md, an unauthenticated user can gain write access to arbitrary locations and potentially overwrite configuration or other critical files, raising the risk of a full compromise if code execution is later achieved through an additional vulnerability or misconfiguration. The flaw is fixed in version 0.30.0.

Affected Systems

The affected product is the open‑source knowns package from the knowns‑dev vendor. Versions 0.29.1 and earlier are released under the npm registry and are marked vulnerable when deployed in the default configuration, where the Management API is served on all interfaces without authentication.

Risk and Exploitability

The CVSS score of 8.8 indicates a high severity for remote, unauthenticated exploitation. The EPSS score is not available, but the lack of authentication and the easy construction of traversal payloads make the vulnerability likely to be exploited in practice. The vulnerability is not yet listed in CISA’s KEV catalog, yet it remains a significant risk for any publicly exposed deployment.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

knowns-dev

knowns

unaffected

Version	Status	Constraints
`0`	affected	< 0.30.0
`0.30.0`	unaffected	—

No data.

Vendor Product Versions

Knowns-dev

Knowns

Version	Status	Scheme	Platform
`[0,0.30.0)`	affected	semver	—
`0.30.0`	unaffected	semver	—

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

Upgrade knowns to version 0.30.0 or later where the path traversal logic has been corrected.
If an immediate upgrade is not feasible, restrict or disable the Management API by binding it only to localhost or by protecting the /api/docs endpoints with authentication and firewalls so that only trusted users can reach the vulnerable endpoints.
As a temporary measure, validate all file paths on the server side to ensure they are resolved inside the documents directory, or replace the vulnerable handlers with a minimal implementation that refuses any path containing '..' fragments.

Generated by OpenCVE AI on September 9, 2026 at 15:30 UTC.

Tracking

Advisories

No advisories available

Metrics

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact Low

Vulnerable System Integrity Impact High

Vulnerable System Availability Impact Low

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact Low

Integrity Impact High

Availability Impact Low

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.747% probability within 30 days)

Exploitation none

Automatable yes

Technical Impact partial

References

Link	Providers
https://github.com/knowns-dev/knowns/security/advisories/GHSA-3h35-4jq7-hv45
https://www.vulncheck.com/advisories/knowns-before-0.30.0-path-traversal-via-document-api

History

Sep 14, 2026 2:30 PM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Sep 10, 2026 4:30 PM First appearance in the feed. Affected vendors updated View changes

Type	Values Removed	Values Added
First Time appeared		Knowns-dev Knowns-dev knowns
Vendors & Products		Knowns-dev Knowns-dev knowns

Sep 9, 2026 1:45 PM Description updated. Title updated. Weaknesses updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
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.
Title		knowns before 0.30.0 Path Traversal via Document API
Weaknesses		CWE-22
References		https://github.com/knowns-dev/knowns/security/advisories/GHSA-3h35-4jq7-hv45 https://www.vulncheck.com/advisories/knowns-before-0.30.0-path-traversal-via-document-api
Metrics		cvssV3_1 `{'score': 8.6, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L'}` cvssV4_0 `{'score': 8.8, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N'}`