CVE-2026-8858 WebSphere Application Server Remote Code Execution
Attackers can achieve remote code execution or denial of service by impersonating the application server and sending crafted responses to the WebSphere Web Server Plug-in.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-8858?
CVE-2026-8858 is a high-severity code injection vulnerability in Ibm I, published on 22 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Weakness: CWE-94
Which versions are affected by CVE-2026-8858?
It affects 1 product.
Products include Ibm I.
How do I fix CVE-2026-8858?
No fix has been published for CVE-2026-8858 yet. Limit exposure of the affected software until one is available.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-8858 being exploited?
There is no known exploitation of CVE-2026-8858 in the wild and no public exploit code.
Other vulnerabilities in Ibm I
- CVE-2026-96119 IBM i is Affected By An Improper Control of Code Generation Vulnerability in HTTP Server Administration GUI
- CVE-2026-16860 IBM i is Affected By Remote Code Execution Vulnerability []
- CVE-2026-17083 IBM i is Affected By Multiple Vulnerabilities in the Debug Server
- CVE-2026-17218 IBM i is Affected By Remote Code Execution Vulnerability in Line Printer Daemon []
- CVE-2026-17276 IBM i is Affected By Multiple Vulnerabilities in Navigator for i
Sources
Also known as GHSA-mfq9-47xf-5654.