CyberSecBulletin
CVE-2026-57496NVD status: Deferred

NetLicensing-MCP: Improper Limitation of a Pathname to a Restricted Directory

Published Updated By the CyberSecBulletin desk

CVE-2026-57496 is a critical-severity improper limitation of a pathname to a restricted directory vulnerability in NetLicensing-MCP from Labs64, with a CVSS 3.1 base score of 9.6 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected NetLicensing-MCP versions: < 0.1.8. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.43% chance of exploitation within 30 days, which is low compared with other CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of NetLicensing-MCP you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
Labs64NetLicensing-MCP< 0.1.8Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N. Scored by CNA (github.com).

Official description

NetLicensing MCP Server is a natural-language interface that enables agentic applications to manage the software-licensing lifecycle in Labs64 NetLicensing. Prior to 0.1.8, netlicensing_get_product passes the caller-controlled product_number to src/netlicensing_mcp/tools/products.py, which interpolates it into a REST path consumed by nl_get() in src/netlicensing_mcp/client.py without path-segment validation. A traversal segment can be normalized from the intended product path to the /token endpoint, after which the response is serialized through _wrap_json instead of _wrap_json_token_read, bypassing redact_token_read() protections for APIKEY number and SHOP shopURL fields. An authenticated MCP client with a non-administrative API key can retrieve plaintext token values, and a recovered administrative token can provide broad read, write, and delete access to the NetLicensing account. This issue is fixed in version 0.1.8.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Limitation of a Pathname to a Restricted Directory

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.

How developers prevent this class of flaw

  • For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
  • Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth.

More Improper Limitation of a Pathname to a Restricted Directory vulnerabilities (CWE-22)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in NetLicensing-MCP

All NetLicensing-MCP vulnerabilities

Recent Improper Limitation of a Pathname to a Restricted Directory vulnerabilities

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