Skip to content

Arbitrary local file read in mcp-memory-keeper context_import via unvalidated filePath

Moderate
mkreyman published GHSA-f7wf-v2vw-mpcx Jun 6, 2026

Package

npm mcp-memory-keeper (npm)

Affected versions

< 0.13.0

Patched versions

0.13.0

Description

Impact

context_import passed the caller-supplied filePath directly to fs.readFileSync with no path confinement. A malicious MCP client — or an LLM agent that is prompt-injected into calling the tool — could point filePath at any file readable by the server process, outside any session or export directory:

  • Full disclosure (JSON files): a valid-JSON target (e.g. another user's exported session, or a *.json credential / service-account file) is parsed and imported into the caller's session, then retrievable verbatim via context_get / context_export.
  • Partial disclosure (any file): for a non-JSON target (e.g. /etc/passwd, an SSH key, a .env), JSON.parse throws and V8 includes a snippet of the file's leading bytes in the SyntaxError message, which was returned verbatim to the caller.

Both ../ traversal and absolute paths worked — there was no path confinement of any kind.

In a typical MCP deployment the server runs on the developer's machine, so the reachable set includes other users' exported memory sessions, JSON credential/config files, and (in leading-bytes form) .env files, SSH keys, and /etc/passwd. The trigger is a tool argument, so the realistic threat model is an LLM agent prompt-injected into calling context_import, or any MCP client connected to the server.

Patches

Fixed in 0.13.0 (PR #36):

  • Imports are confined to a server-owned exports directory (<DATA_DIR>/exports, overridable via MEMORY_KEEPER_EXPORT_DIR), resolved with realpathSync. ../ traversal, absolute paths outside the directory, and symlink escapes are all rejected.
  • File read and JSON.parse are separate operations; read/parse failures return a generic message and never echo file bytes (the SyntaxError-message leak is gone). The database-write path is likewise generic.
  • An E2E security regression suite covers the reported arbitrary-read and traversal vectors, plus symlink escape, the directory-prefix boundary, and a no-existence-oracle check.

Workarounds

Upgrade to >= 0.13.0. There is no configuration-only workaround for affected versions.

References

  • Report: GitHub issue #35
  • Fix: PR #36

Credit

Reported by Zhihao Zhang (@mcfly-zzh).

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Local
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVE ID

CVE-2026-54561

Weaknesses

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. Learn more on MITRE.

Generation of Error Message Containing Sensitive Information

The product generates an error message that includes sensitive information about its environment, users, or associated data. Learn more on MITRE.

Credits