CVE-2018-1000863
HIGHCVE-2018-1000863 is a high-severity (CVSS 8.2) Path Traversal vulnerability in org.jenkins-ci.main:jenkins-core. 1 public exploit reference exists, so weaponization risk is real. O3 Security confirms whether CVE-2018-1000863 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Improper Limitation of a Pathname to a Restricted Directory in Jenkins
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 data modification vulnerability exists in Jenkins 2.153 and earlier, LTS 2.138.3 and earlier in User.java, IdStrategy.java that allows attackers to submit crafted user names that can cause an improper migration of user record storage formats, potentially preventing the victim from logging into Jenkins.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.jenkins-ci.main:jenkins-core | all versions | 2.138.4 |
| ☕Maven | org.jenkins-ci.main:jenkins-core | ≥ 2.140&&< 2.154 | 2.154 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
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. 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 2.138.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2018-1000863 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-2018-1000863 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-2018-1000863. 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-2018-1000863 in your dependencies?
O3 detects CVE-2018-1000863 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.