When the Microsoft SMTP service attempts to send a message to a server and receives a 4xx error code, it quickly and repeatedly attempts to redeliver the message, causing a denial of service.
Loading...
Loading...
When the Microsoft SMTP service attempts to send a message to a server and receives a 4xx error code, it quickly and repeatedly attempts to redeliver the message, causing a denial of service.
March 1, 1999
April 16, 2026
Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.
See which npm, PyPI, Go, and Maven packages are affected by CVE-1999-0419
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.