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MEDIUM severity

CVE-2026-57300 — mcp-server

MEDIUMFix: jenkinsci/mcp-server-plugin@ffe5ae7

CVE-2026-57300 is a medium-severity (CVSS 4.3) CWE-862 vulnerability in io.jenkins.plugins:mcp-server. A fix is available for io.jenkins.plugins:mcp-server — see the affected versions and patch details below.

Jenkins MCP Server Plugin missing a permission check

Published
Updated
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Sep 28, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-57300.

EPSS Exploitation Probability

via FIRST.org ↗
0.3%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs18th percentile — riskier than 18% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2026-57300 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 394,415 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg affected
☕io.jenkins.plugins:mcp-server

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

Jenkins MCP Server Plugin 0.177.v629fdb_2557fe and earlier does not perform a permission check in the getReplayScripts MCP tool that returns the replay script of a Pipeline build.

This allows attackers with Item/Read permission to obtain the Pipeline script of jobs.

MCP Server Plugin 0.178.vffe5a_e770f3b_ requires Item/Extended Read permission to return the replay script of a Pipeline build through the getReplayScripts MCP tool.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
☕Mavenio.jenkins.plugins:mcp-serverall versions0.178.vffe5aio.jenkins.plugins:mcp-server:0.178.vffe5a

Affected Products

1 product · 1 configurations
Application
mcp serverjenkins
≤ 0.177.v629fdb_2557fe
range

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for io.jenkins.plugins:mcp-server, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update io.jenkins.plugins:mcp-server to 0.178.vffe5a or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-57300 is resolved across your whole dependency graph.

  3. Workarounds

    Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Frequently Asked Questions

Jenkins MCP Server Plugin 0.177.v629fdb_2557fe and earlier does not perform a permission check in the getReplayScripts MCP tool that returns the replay script of a Pipeline build. This allows attackers with Item/Read permission to obtain the Pipeline script of jobs. MCP Server Plugin 0.178.vffe5a_e770f3b_ requires Item/Extended Read permission to return the replay script of a Pipeline build through the getReplayScripts MCP tool.
O3 Security · Impact-Aware SCA

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CVE-2026-57300: mcp-server — Fixed in 0.178.vffe5a