Server metadata could be exposed because one of the error messages reflected the whole response back to the client in JetBrains TeamCity versions before 2018.2.5 and UpSource versions before 2018.2 build 1293.
Conclusion & alert: CVE-2019-12156 is rated Low Risk (21.2/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.00%).Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
Exploit prediction scoring system (EPSS) score for CVE-2019-12156
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).