CVE-2021-20517: IBM WebSphere Application Server Nd

High severity, CVSS 8.8. EPSS: 1.9% chance of exploitation in the next 30 days.

IBM WebSphere Application Server Network Deployment 8.5 and 9.0 could allow a remote authenticated attacker to traverse directories. An attacker could send a specially-crafted URL request containing "dot dot" sequences (/../) to read and delete arbitrary files on the system. IBM X-Force ID: 198435.

Affected products

• IBM WebSphere Application Server Nd: from 8.5.0.0, before 8.5.5.20 (fixed in 8.5.5.20); from 9.0.0.0, before 9.0.5.8 (fixed in 9.0.5.8)

Published 2021-06-07. Last modified 2026-06-17.