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Vulnerabilities

Vulnerability · CVE-2026-57496

NetLicensing MCP Server is a natural-language interface that enables agentic applications to manage the software-licensing lifecycle in Labs64 NetLicensing.

Published Jun 18, 2026 · catalog updated Oct 15, 2026 · NetLicensing MCP Server is

Check if you run it

No confirmed exploitation is on record for CVE-2026-57496. EPSS is 0.35%. Act only if a listed version of NetLicensing MCP Server is is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (NetLicensing MCP Server is).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Critical9.6
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.35%
Remediation
Advisory link
Affected products
PyPI netlicensing-mcp

## REST Path Traversal Bypasses Token Redaction in netlicensing-mcp ### Summary The MCP tool in interpolates a caller-controlled argument directly into a REST URL path without any validation. Passing as the product number causes to normalize into , silently redirecting the request to the NetLicensing token endpoint instead of the intended product endpoint. The response is then serialized through the generic wrapper rather than the token-specific wrapper, bypassing all APIKEY and SHOP redaction. An authenticated MCP client can recover plaintext API key values that the token read tools intentionally mask, including admin-level APIKEY credentials. ### Details The vulnerability is a path traversal (CWE-22) that exploits the interaction between unsanitized string interpolation and 's WHATWG URL normalization. **Source — ** is inserted directly into the REST path with no validation. A value of produces the path . **Sink — ** constructs the full URL as and, per WHATWG URL normalization rules applied to absolute URLs, resolves it to . The HTTP request is therefore sent to the NetLicensing endpoint. **Redaction bypass — and ** The tool handler wraps the response via , which calls only the generic redaction. The token-specific path → is never invoked. The function at is the only code that masks APIKEY and SHOP fields; because it is not on this code path, the raw API key value is returned verbatim in the MCP tool output. **Complete data flow:** 1. — MCP dispatcher receives attacker-controlled and calls . 2. — value interpolated into without validation. 3. — ; normalizes and sends request to endpoint. 4. — response wrapped as via , not . 5. — generic redaction applies only default-field masking. 6. — with APIKEY/SHOP-specific masking is never reached. ### PoC **Prerequisites** - Python 3.10+ - 0.1.5 (or local commit ) installed or available via - , , installed **Option A — Docker (recommended, reproduces Phase 2 result)** **Option B — Direct Python** **Expected output** The fie

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Enter the version you run. The result uses only the ranges stored on this record.

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  • PyPI netlicensing-mcp0 → 0.1.8

How to fix CVE-2026-57496

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-57496. EPSS is 0.35%. Act only if a listed version of NetLicensing MCP Server is is installed.

Which versions are affected?

Compare what you have installed with 0 → 0.1.8. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-22: Path Traversal. EPSS 0.35%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Jul 23, 2026 · GitHub Advisory Database

    Fix available

    netlicensing-mcp fixed in 0.1.8

  2. Oct 15, 2026 · NIST NVD

    Detected

    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

  3. Oct 15, 2026 · GitHub Advisory Database

    Fix available

    netlicensing-mcp fixed in 0.1.8

Sources

  • CVE.orgVulnerability recordCVE-2026-57496

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-57496

    30-day exploitation probability 0.4%

    first.org
  • GitHub Advisory DatabasePackage advisoryGHSA-hxpf-9xvq-wph8

    GitHub Advisory Database record mirrored by OSV.

    github.com
  • NIST NVDVulnerability recordCVE-2026-57496

    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

    nvd.nist.gov
  • OpenSSF OSV / OSV ScannerPackage advisoryGHSA-hxpf-9xvq-wph8

    netlicensing-mcp: REST Path Traversal Bypasses Token Redaction

    osv.dev

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.