CVE-2018-1999001 is a high-severity (CVSS 8.8) vulnerability in org.jenkins-ci.main:jenkins-core. EPSS puts its 30-day exploitation probability at 18.1% (97th percentile). A fix is available for org.jenkins-ci.main:jenkins-core — see the affected versions and patch details below.
Improper Input Validation in Jenkins
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2018-1999001 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the 10–50% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
org.jenkins-ci.main:jenkins-core☕org.jenkins-ci.main:jenkins-coreReal-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
A unauthorized modification of configuration vulnerability exists in Jenkins 2.132 and earlier, 2.121.1 and earlier in User.java that allows attackers to provide crafted login credentials that cause Jenkins to move the config.xml file from the Jenkins home directory. If Jenkins is started without this file present, it will revert to the legacy defaults of granting administrator access to anonymous users.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.jenkins-ci.main:jenkins-core | all versions | 2.121.2org.jenkins-ci.main:jenkins-core:2.121.2 |
| ☕Maven | org.jenkins-ci.main:jenkins-core | ≥ 2.122&&< 2.132 | 2.132org.jenkins-ci.main:jenkins-core:2.132 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.jenkins-ci.main:jenkins-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.jenkins-ci.main:jenkins-core to 2.121.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2018-1999001 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2018-1999001 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2018-1999001. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2018-1999001 in your dependencies?
O3 Security finds CVE-2018-1999001 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.