{"id":"CVE-2026-55887","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-55887","generatedAt":"2026-10-28T03:30:47.174Z","title":"MCP Gateway allows easy and secure running and deployment of MCP servers.","description":"MCP Gateway allows easy and secure running and deployment of MCP servers. From 0.21.0 until 0.42.2, Docker MCP Gateway YAML-unmarshalled the attacker-controlled io.docker.server.metadata OCI image label into the broad catalog.Server structure for direct docker:// references and catalog snapshot imports in pkg/oci/self_contained.go and pkg/workingset/workingset.go. Runtime-shaping fields including Volumes, User, and ExtraHosts were then appended to the docker run argument vector without an origin allowlist, allowing a malicious image author to request host filesystem or Docker socket mounts and UID 0 execution when a victim selected or pulled the image. This container-creation-time boundary bypass can execute arbitrary code on the host and is not prevented by no-new-privileges because no in-container privilege escalation is required. This issue is fixed in version 0.42.2.","published":"2026-09-15T16:17:17.000Z","lastModified":"2026-09-30T17:51:56.000Z","status":"Deferred","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"4.0","score":8.7,"severity":"HIGH","vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-88"],"affected":[],"epss":{"score":0.00222,"percentile":0.12695,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.22%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://github.com/docker/mcp-gateway/commit/306d2d94a3b526f43281313321bf784f2d46a7fe","source":"security-advisories@github.com"},{"url":"https://github.com/docker/mcp-gateway/commit/439b2200d9e26a4ff414aeb043785df45a78422b","source":"security-advisories@github.com"},{"url":"https://github.com/docker/mcp-gateway/pull/498","source":"security-advisories@github.com"},{"url":"https://github.com/docker/mcp-gateway/releases/tag/v0.42.2","source":"security-advisories@github.com"},{"url":"https://github.com/docker/mcp-gateway/security/advisories/GHSA-r2xf-7jw5-pjg6","source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-55887","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}