What is CVE-2026-8620?
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 HTTP request smuggling in the Web Server Plug-ins through a specially crafted request.
The record classifies CVE-2026-8620 under weakness class CWE-444. 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. 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
- 7.5 — HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:L/A:N - EPSS (FIRST)
- 0.3% probability of exploitation in the next 30 days, higher than 29.0% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 4.9/10 — 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-2026-8620 being exploited?
It currently carries a trending score of 12 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-2026-8620
No vendor patch reference has been recorded for CVE-2026-8620 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-2026-8620
1 tracked threat in the Threadlinqs corpus references CVE-2026-8620, 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 .