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VulnerabilityCVE-2026-8633Published 2026-05-26

CVE-2026-8633 — IBM Web Server Plug-ins for WebSphere Application Server and WebSphere Liberty

critical

As of 2026-05-27, CVE-2026-8633 is a CRITICAL-severity vulnerability in IBM Web Server Plug-ins for WebSphere Application Server and WebSphere Liberty, CVSS v3.1 9.8, EPSS 0.9% (59.8th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-8633, most recently “IBM WebSphere Application Server & Liberty Web Server Plug-ins Unauthenticated RCE and HTTP Request Smuggling (CVE-2026-8633, CVE-2026-8620)”.

CVSS v3.1
9.8/10Critical
EPSS
0.9%Higher than 59.8% of scored CVEs
CISA KEV
NoNot in the KEV catalog
Tracked threats
1Campaigns referencing it
Priority
7.3/10Threadlinqs triage score
Published
Updated 2026-05-27
CVSS v3.1 9.8 (CRITICAL) · EPSS 0.9% (higher than 59.8% of all scored CVEs) · Priority 7.3/10 · Published 2026-05-26

Last updated:

What is CVE-2026-8633?

IBM Web Server Plug-ins for WebSphere Application Server and WebSphere Liberty 8.5, 9.0 IBM WebSphere Application Server and WebSphere Application Server Liberty are vulnerable to remote code execution in the Web Server Plug-ins, through a specially crafted request.

The record classifies CVE-2026-8633 under weakness class CWE-94. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 138 days ago.

Severity and exploitation probability

CVSS v3.1 base score
9.8 — CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (FIRST)
0.9% probability of exploitation in the next 30 days, higher than 59.8% of all scored CVEs
CISA KEV
Not listed in the CISA Known Exploited Vulnerabilities catalog
Threadlinqs priority
7.3/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
Published
2026-05-26, last modified 2026-05-27

Is CVE-2026-8633 being exploited?

It currently carries a trending score of 20 in the Threadlinqs vulnerability feed.

Affected products and versions

  • IBM: Web Server Plug-ins for WebSphere Application Server and WebSphere Liberty

How to fix CVE-2026-8633

No vendor patch reference has been recorded for CVE-2026-8633 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

Threat activity tracking CVE-2026-8633

1 tracked threat in the Threadlinqs corpus references CVE-2026-8633, either in the campaign’s CVE list or as an indicator on the campaign record.

Sources

Enriched from CVE.org, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on .

Vendor advisory and patch