---
id: "CVE-2018-1000861"
kind: "vulnerability"
aliases: ["CVE-2018-1000861"]
title: "Jenkins Jenkins Stapler Web Framework: Jenkins Stapler Web Framework Deserialization of Untrusted Data Vulnerability"
severity: "critical"
cvss: 10.0
epss: 0.98326
exploited: true
status: "open"
category: "runtime"
products: [{"name": "Jenkins Jenkins Stapler Web Framework", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["ci-cd", "exploited", "jenkins", "runtime", "self-hosted"]
not_affected_if: ["managed-hosting"]
published_at: "2018-12-10T14:29:01+00:00"
first_seen_at: "2026-10-23T19:11:53+00:00"
updated_at: "2026-10-23T21:57:35+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2018-1000861", "first_seen_at": "2026-10-23T19:11:53+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2018-1000861", "first_seen_at": "2026-10-23T19:13:44+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2018-1000861", "first_seen_at": "2026-10-23T21:57:35+00:00"}]
---

# Jenkins Jenkins Stapler Web Framework: Jenkins Stapler Web Framework Deserialization of Untrusted Data Vulnerability

The Stapler web framework used by Jenkins deserializes untrusted data, letting a remote request run code. An attacker who can reach the Jenkins web interface gets code execution on the Jenkins server.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:Jenkins Jenkins Stapler Web Framework affected ? fixed ?

## Fix

Apply the Jenkins and Stapler updates from the vendor advisory; the sources do not name the fixed version.

## Timeline

- 2026-10-23T19:11:53+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2018-1000861
- 2026-10-23T19:13:44+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2018-1000861
- 2026-10-23T21:57:35+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2018-1000861

## From the sources

A code execution vulnerability exists in the Stapler web framework used by Jenkins 2.153 and earlier, LTS 2.138.3 and earlier in stapler/core/src/main/java/org/kohsuke/stapler/MetaClass.java that allows attackers to invoke some methods on Java objects by accessing crafted URLs that were not intended to be invoked this way.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_