CVE-2026-57496 NetLicensing MCP Server: REST Path Traversal Bypasses Token Redaction
Path traversal allows authenticated users to bypass token redaction and retrieve plaintext API keys, potentially leading to full account compromise.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-57496?
CVE-2026-57496 is a critical path traversal vulnerability in Labs64 NetLicensing-MCP, published on 15 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
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.
Weakness: CWE-22
Which versions are affected by CVE-2026-57496?
3 open source packages ship an affected version, including netlicensing-mcp.
| Package | Affected | Fixed in |
|---|---|---|
netlicensing-mcp PyPI | All versions | 0.1.8 |
netlicensing-mcp PyPI | All versions | 0.1.8 |
netlicensing-mcp PyPI | All versions | 0.1.8 |
How do I fix CVE-2026-57496?
Upgrade netlicensing-mcp to 0.1.8 or later.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-57496 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-57496 exists.
Sources
Also known as GHSA-hxpf-9xvq-wph8, PYSEC-2026-3489.