# CVE-2026-8646 — IBM WebSphere Application Server

> As of 2026-06-22, CVE-2026-8646 is a HIGH-severity vulnerability in IBM WebSphere Application Server, CVSS v3.1 7.4, EPSS 0.3% (27.0th percentile). No Threadlinqs-tracked threat campaign has been attributed to CVE-2026-8646 as of 2026-06-22; the identifier is re-checked against the Threadlinqs threat corpus on every daily ingest.

**Last updated:** 2026-06-22

## What is CVE-2026-8646?

IBM WebSphere Application Server 9.0 and 8.5 and IBM WebSphere Application Server - Liberty 17.0.0.3 through 26.0.0.6 are vulnerable to HTTP request smuggling. A remote attacker could smuggle a specially crafted request to the application server thereby allowing the attacker to bypass security controls, spoof identity, escalate privilege, and expose sensitive information.

The record classifies CVE-2026-8646 under weakness class [CWE-444](https://intel.threadlinqs.com/cwe/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, integrity. 2 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 105 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 7.4 — HIGH (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N`)
- **EPSS (FIRST):** 0.3% probability of exploitation in the next 30 days, higher than 27.0% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 4.8/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-06-22

## Is CVE-2026-8646 being exploited?

It currently carries a trending score of 37 in the Threadlinqs vulnerability feed.

## Affected products and versions

- [IBM](https://intel.threadlinqs.com/vendors/ibm): WebSphere Application Server, WebSphere Application Server - Liberty

## How to fix CVE-2026-8646

No vendor patch reference has been recorded for CVE-2026-8646 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-2026-8646

No threat campaign in the Threadlinqs corpus currently references CVE-2026-8646, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.

## Sources

Enriched from CVE.org, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on 2026-06-23.

**Vendor advisory and patch**

- [ibm.com — vendor advisory](https://www.ibm.com/support/pages/node/7276579)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-8646
Full detection coverage and IOCs for threats exploiting CVE-2026-8646 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp