CVE-2026-81093: Server-Side Request Forgery (SSRF) in apify actors-mcp-server

The get-html-skeleton tool in apify actors-mcp-server versions before 0.9.12 performs insufficient validation on user-supplied URLs, only checking that the URL starts with http or https and is syntactically valid. It does not restrict URLs to external hosts, allowing requests to internal IP ranges including loopback, link-local, and private addresses. This enables an attacker to induce the server to fetch internal resources, such as cloud provider instance metadata endpoints, and return their contents. The vulnerability is mitigated by the removal of the get-html-skeleton tool in version 0.9.12.

An unauthenticated attacker can exploit this SSRF vulnerability to make the server request internal network resources that are otherwise inaccessible externally. This includes cloud instance metadata services that may contain sensitive credentials or configuration data. The attacker can read the fetched content in the tool response, potentially leading to information disclosure and further compromise of the hosting environment.

Version 0.9.12 of apify actors-mcp-server removes the vulnerable get-html-skeleton tool, effectively mitigating the SSRF vulnerability. Users should upgrade to version 0.9.12 or later to remediate this issue. No other official remediation or patch is indicated. Patch status is not explicitly confirmed beyond the removal of the tool; users should consult vendor advisories for any additional guidance.