How severe is CVE-2018-1999001?

CVE-2018-1999001 has a CVSS score of 8.8/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2018-1999001?

CVE-2018-1999001 affects the following packages: org.jenkins-ci.main:jenkins-core (Maven), org.jenkins-ci.main:jenkins-core (Maven). Ecosystems affected: Maven.

How do I fix CVE-2018-1999001?

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.

How do I detect CVE-2018-1999001 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.jenkins-ci.main:jenkins-core. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2018-1999001 if there is no patch (or I can't update yet)?

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 does O3 Security protect against CVE-2018-1999001?

O3 pinpoints whether CVE-2018-1999001 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2018-1999001 actively exploited in the wild?

No public exploit code has been indexed for CVE-2018-1999001 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2018-1999001?

CVE-2018-1999001 has an EPSS (Exploit Prediction Scoring System) score of 18.1%, placing it in the 97th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score warrants monitoring and prompt remediation.

When was CVE-2018-1999001 published, and has it been updated?

CVE-2018-1999001 was published on July 23, 2018 and was last updated on April 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2018-1999001: Improper Input Validation in Jenkins (High 8.…

EPSS Exploitation Probability

via FIRST.org ↗

18.1%probability of exploitation in next 30 days

Moderate Risk97th percentile-9.20%

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.

Blast Radius

2 pkgs affected

☕org.jenkins-ci.main:jenkins-core☕org.jenkins-ci.main:jenkins-core

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

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

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.jenkins-ci.main:jenkins-core`	all versions	2.121.2
☕Maven	`org.jenkins-ci.main:jenkins-core`	≥ 2.122&&< 2.132	2.132

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.jenkins-ci.main:jenkins-core. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
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 pinpoints whether CVE-2018-1999001 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

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

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.

O3 Security · Impact-Aware SCA

Is CVE-2018-1999001 in your dependencies?

O3 detects CVE-2018-1999001 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works

CVE-2018-1999001