CVE-2026-55887

HIGHPre-NVD 8.78.7
EchelonGraph scoreLOW confidence

This high-severity CVE scores 8.7 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: secondary
Trending — 3 sources updated this week
8.7EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.7Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
8.7
EG Score
8.7(low)
EG Risk
39(Track)
EG Risk 39/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity87% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
10%
KEV
Not listed

Published

June 18, 2026

Last Modified

September 15, 2026

Advisory Details (5)

Auto-updated Sep 15, 2026
Patch available. Sources: github_commit, github_release, github, github_pr.
github_release Patch Available

v0.42.2

Patch available: docker/mcp-gateway v0.42.2 (pre-release)

https://github.com/docker/mcp-gateway/releases/tag/v0.42.2
github_commit

commit 439b2200d9e2 (docker/mcp-gateway)

Fix landed in docker/mcp-gateway commit 439b2200d9e2 — awaiting tagged release

https://github.com/docker/mcp-gateway/commit/439b2200d9e26a4ff414aeb043785df45a78422b
github_commit

commit 306d2d94a3b5 (docker/mcp-gateway)

Fix landed in docker/mcp-gateway commit 306d2d94a3b5 — awaiting tagged release

https://github.com/docker/mcp-gateway/commit/306d2d94a3b526f43281313321bf784f2d46a7fe
github_pr

Narrow OCI label schema to descriptive fields only

Fix merged in docker/mcp-gateway PR #498 on 2026-05-27 — awaiting tagged release

https://github.com/docker/mcp-gateway/pull/498
github Patch Available

Argument injection via OCI image label YAML in Docker MCP Gateway · Advisory · docker/mcp-gateway · GitHub

https://github.com/docker/mcp-gateway/security/advisories/GHSA-r2xf-7jw5-pjg6

Vendor Advisories for CVE-2026-55887(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
Go(1)
PackageVulnerable rangeFixed inDependents
github.com/docker/mcp-gateway—0.42.2—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 8× in last 7d / 8× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-17 19:31 UTCEPSS rescore
  3. 2026-09-16 14:08 UTCEPSS rescore
  4. 2026-09-15 19:41 UTCEG score recompute
  5. 2026-09-15 18:25 UTCEG score recompute
  6. 2026-09-15 16:36 UTCEG score recompute
  7. 2026-09-15 15:48 UTCEG score recompute▲ 8.70
  8. 2026-09-15 15:47 UTCMITRE cvelistV5CVSS v3 → 8.7 · CVSS v4 → 8.7
  9. 2026-08-01 09:29 UTCEG score recompute
  10. 2026-07-26 18:48 UTCEG score recompute
  11. 2026-07-23 03:20 UTCEG score recompute
  12. 2026-06-18 13:07 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-55887?
CVE-2026-55887 is a high vulnerability published on June 18, 2026. 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…
When was CVE-2026-55887 disclosed?
CVE-2026-55887 was first published in the National Vulnerability Database on June 18, 2026, with the most recent update on September 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55887 actively exploited?
CVE-2026-55887 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 90.0% of all scored CVEs.
What is the CVSS score of CVE-2026-55887?
CVE-2026-55887 has a CVSS v3 base score of 8.7 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-55887?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55887, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-55887

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