CVE-2026-8858: WebSphere Application Server Remote Code Execution

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-22 · updated 2026-10-25
Weakness: CWE-94

Description

IBM WebSphere Application Server and IBM WebSphere Application Server Liberty are vulnerable to remote code execution and denial of service in the WebSphere Web Server Plug-in component. This vulnerability can be exploited when an attacker impersonates the application server and sends crafted responses to the plug-in.

Affected products

IBM i: from 7.3 through 7.6

References

https://www.ibm.com/support/pages/node/7276560

Get alerted when CVE-2026-8858 or the next vulnerability affects your stack