CVE-2018-1999001: Improper Input Validation in Jenkins
Summary
CVE-2018-1999001: Improper Input Validation in Jenkins. Affects org.jenkins-ci.main:jenkins-core across 2 version ranges.
< 2.121.2
>= 2.122, < 2.132
Fixed in 2.121.2 or 2.132, depending on the release line you run. How to fix ↓
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Background
Jenkins is an open-source automation server that enables developers to build, test, and deploy their software projects. It provides a wide range of features and plugins to support continuous integration and delivery. The vulnerable package in focus is 'org.jenkins-ci.main:jenkins-core'.
Vulnerability Detail
The vulnerability, identified as CVE-2018-1999001, is an unauthorized modification of configuration issue in Jenkins. It affects versions 2.132 and earlier, as well as 2.121.1 and earlier. The vulnerability resides in the User.java file and allows attackers to provide crafted login credentials, leading to the relocation of the config.xml file from the Jenkins home directory. If the config.xml file is missing, Jenkins reverts to the legacy defaults, granting administrator access to anonymous users. This vulnerability has a CVSS score of 8.8, indicating a high severity level.
How To Fix
Latest published version: 2.587 as of 22 Oct 2026
Upgrading to it may include breaking changes; the versions below are the minimum fixed release for this vulnerability.
If you can't move to the latest
The minimum fixed version depends on the release line you run.
-
< 2.121.22.121.2 -
>= 2.122, < 2.1322.132
Tip — Not sure which release line you're on? Vulert can find the fix for the version you are using. Scan free →
Workaround
There is no specific workaround mentioned for this vulnerability. Users are advised to follow the recommended fix and upgrade to the patched versions of Jenkins.
Conclusion
The unauthorized modification of configuration vulnerability in Jenkins can be mitigated by upgrading to the fixed versions mentioned. It is crucial to promptly address this vulnerability to prevent unauthorized access and ensure the security of Jenkins installations. For further assistance and support in vulnerability remediation, please contact DevNack.com.
See every vulnerability recorded for org.jenkins-ci.main:jenkins-core →
FAQ
Jenkins is an open-source automation server used for continuous integration and delivery of software projects.
This vulnerability allows attackers to gain administrator access to Jenkins by providing crafted login credentials.
Versions 2.132 and earlier, as well as 2.121.1 and earlier, are affected by this vulnerability.
To fix this vulnerability, upgrade to Jenkins version 2.121.2 or later if using versions 2.121.1 or earlier. For versions 2.122 and later, upgrade to version 2.132 or later.
No specific workaround is mentioned. It is recommended to upgrade to the patched versions of Jenkins.
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