CVE-2026-86775VulnerabilityPublished 09/09/2026Updated 09/14/2026

CVE-2026-86775: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') in knowns-dev knowns

Affects knowns-dev knownsSource CVE Database V5

Not known to be exploited · CVSS 8.8 High · fixed in 0.30.0 : patch knowns-dev knowns soon.

Data as of 10/24/2026, 22:16:05 UTC

CVSS 4.0 base score

8.8High

How severe the flaw is on the 0–10 CVSS scale.

Exploitation: Not in CISA KEV, no exploitation reported
EPSS: 0.7% chance of exploitation in 30 days – higher than 54% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 0.30.0

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

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: Low
Vulnerable system integrity: High
Vulnerable system availability: Low
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the Vulnerable System.
Vulnerable system integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the vulnerable system. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the vulnerable system.
Vulnerable system availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the Vulnerable System are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

What to do

Affected software

Product	Affected	Fixed in
knowns-devknowns	Affected <0.30.0	Fixed in 0.30.0
npmknowns-dev/knowns`pkg:npm/knowns-dev/knowns`Other threats	Affected <=0.29.1	Fixed in–

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AI-suggested

Upgrade knowns to version 0.30.0 or later, where this path traversal vulnerability is fixed. Until then, restrict access to the Management API to trusted users and networks to prevent exploitation. Patch status is confirmed fixed in version 0.30.0.

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.

Impact

Remote unauthenticated attackers can exploit this vulnerability to perform arbitrary file read, write, create, and delete operations on files with a .md extension anywhere on the host filesystem. This can lead to exposure of sensitive data, corruption or destruction of files, and an arbitrary-write primitive that may be leveraged for code execution. The vulnerability affects deployments where the Management API is unauthenticated and accessible.

Summary

The knowns package versions <= 0.29.1 have a path traversal vulnerability in the Document API's HTTP handler. The function cleanDocPath() strips certain characters but fails to neutralize '../' sequences, allowing attackers to traverse directories. The target path is constructed without verifying it remains within the documents directory, enabling arbitrary file operations on .md files anywhere on the host filesystem. In default deployments where the Management API is unauthenticated and exposed, remote unauthenticated attackers can exploit this to read, create, overwrite, or delete files and directories, potentially exposing sensitive data or enabling further code execution. The issue is resolved in version 0.30.0.

References

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