---
title: "CVE-2026-57496: netlicensing-mcp: REST Path Traversal Bypasses Token Redaction"
url: https://erroneo.us/security/cve/CVE-2026-57496/
description: "CVE-2026-57496 (netlicensing-mcp (PyPI)): NetLicensing MCP Server is a natural-language interface that enables agentic applications to manage the…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-10-15
date_modified: 2026-10-21
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-57496"
kev: false
cvss: 9.6
epss: 0.00353
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-57496: netlicensing-mcp: REST Path Traversal Bypasses Token Redaction

**Signal:** Critical, preconditions apply. Severe if exploited, but exploitation needs conditions that may not apply to you. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Not in CISA KEV , but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.4% , percentile 28: FIRST’s model estimates a 0.4% chance of exploitation activity in the next 30 days, higher than 28% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Needs an account (low (any account)). Exposure depends on who can log in.
- Only applies if your dependency tree includes netlicensing-mcp (PyPI) < 0.1.8, fixed in 0.1.8 . Check your lockfile, including transitive dependencies.

## What it is

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, netlicensinggetproduct passes the caller-controlled productnumber to src/netlicensingmcp/tools/products.py, which interpolates it into a REST path consumed by nlget() in src/netlicensingmcp/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 wrapjson instead of wrapjsontokenread, bypassing redacttokenread() 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.

## Affected packages

- PyPI `netlicensing-mcp` < 0.1.8 → fixed: 0.1.8

## Affected products (CVE record)

- Labs64 NetLicensing-MCP: < 0.1.8

## Severity

- GitHub_M CVSS 3.1: 9.6 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N`
- GitHub CVSS 3.1: 9.6 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.35% probability of exploitation activity in the next 30 days; percentile 28.

## Sources

- [GitHub Advisory GHSA-hxpf-9xvq-wph8](https://github.com/advisories/GHSA-hxpf-9xvq-wph8)
- [CVE.org record CVE-2026-57496](https://www.cve.org/CVERecord?id=CVE-2026-57496)
- [NVD entry CVE-2026-57496](https://nvd.nist.gov/vuln/detail/CVE-2026-57496)
- [github.com](https://github.com/Labs64/NetLicensing-MCP/security/advisories/GHSA-hxpf-9xvq-wph8)
- [github.com](https://github.com/Labs64/NetLicensing-MCP/pull/6)
- [github.com](https://github.com/Labs64/NetLicensing-MCP/commit/b8fd0ea76d533202573eb24add9fb2fbd9331496)
- [github.com](https://github.com/Labs64/NetLicensing-MCP/releases/tag/0.1.8)
- [github.com](https://github.com/pypa/advisory-database/tree/main/vulns/netlicensing-mcp/PYSEC-2026-3489.yaml)

---
Source page: https://erroneo.us/security/cve/CVE-2026-57496/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt