How severe is CVE-2026-8858?

CVE-2026-8858 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over an adjacent network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-8858 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-8858?

CVE-2026-8858 affects Ibm I. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-8858?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-8858 have an EU (EUVD) identifier?

Yes. CVE-2026-8858 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-38284.

When was CVE-2026-8858 published?

CVE-2026-8858 was published on 2026-06-22 and last updated on 2026-06-24.

CVE-2026-8858

CVE-2026-8858 is a high-severity vulnerability in Ibm I with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-94.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 0% (17th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-38284
Weakness: CWE-94
Affected product: Ibm I
Published: 2026-06-22
Last modified: 2026-06-24

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.

Frequently asked questions

What is CVE-2026-8858?: 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.
How severe is CVE-2026-8858?: CVE-2026-8858 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over an adjacent network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-8858 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-8858?: CVE-2026-8858 affects Ibm I. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-8858?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-8858 have an EU (EUVD) identifier?: Yes. CVE-2026-8858 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-38284.
When was CVE-2026-8858 published?: CVE-2026-8858 was published on 2026-06-22 and last updated on 2026-06-24.

References

https://www.ibm.com/support/pages/node/7277344

Affected products (1)

cpe:2.3:a:ibm:i:*:*:*:*:*:*:*:*

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