CVE-2026-8400: IBM WebSphere Application Server 8.5, and 9.0 and IBM WebSphere Application Server - Liberty Continuous delive

This month

HIGH 8.1REMOTEDOWNGRADE

CVE-2026-8400 is a high-severity flaw (CVSS 8.1) affecting websphere application server. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

IBM WebSphere Application Server 8.5, and 9.0 and IBM WebSphere Application Server - Liberty Continuous delivery has a flaw in the ORB component in IBM SDK, Java Technology Edition, may allow a malicious IIOP server to induce loading and instantation of arbitrary classes.

Why this priority

High severity
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	8.1 (High)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.5% (top 59%)
CISA exploited list	No
Weakness	CWE-470
Published	2026-08-05
Last modified	2026-08-10

Publisher (CNA): IBM Corporation · Vendor: ibm

Last updated 2026-08-10 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-08-05 16:17 UTCPublished CVE record published
2026-08-10 15:57 UTCUpdated Record last modified

ibm websphere application server DOWNGRADE

Affected: all versions · 8.5.0.0 · 9.0.0.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 8.5.0.0

1. Check installed version

apt-cache policy websphere-application-server || rpm -q websphere-application-server || websphere-application-server --version

2. No fixed release: DOWNGRADE to a release before 8.5.0.0 (Debian / Ubuntu)

apt-cache madison websphere-application-server sudo apt install websphere-application-server=<VERSION_BEFORE_8.5.0.0> sudo apt-mark hold websphere-application-server

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list websphere-application-server sudo dnf downgrade websphere-application-server-<VERSION_BEFORE_8.5.0.0> sudo dnf versionlock add websphere-application-server

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-8400?

websphere application server: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-8400 being exploited?

CVE-2026-8400 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-8400 affect?

CVE-2026-8400 affects websphere application server. Severity is high (CVSS 8.1). IBM WebSphere Application Server 8.5, and 9.0 and IBM WebSphere Application Server - Liberty Continuous delivery has a flaw in the ORB component in IBM SDK, Java Technology Edition, may allow a malicious IIOP server to induce loading and in

How urgent is CVE-2026-8400?

Priority 44/100. High severity; Remotely exploitable, no login, no user action

Software pages

Java vulnerabilities · IBM WebSphere vulnerabilities

Related CVEs

CVE-2026-3621 HIGH 7.5 UPGRADE IBM WebSphere Application Server - Liberty 17.0.0.3 through 26.0.0.4 IBM WebSphere Application Server Liberty
CVE-2026-5516 MEDIUM 4.4 UPGRADE IBM WebSphere Application Server - Liberty 22.0.0.11 through 26.0.0.5 IBM WebSphere Application Server Liberty
CVE-2026-10845 HIGH 7.3 UPGRADE IBM WebSphere Application Server 8.5 and 9.0 could allow a remote attacker to bypass authentication and gain u
CVE-2026-9006 HIGH 7.4 UPGRADE IBM WebSphere Application Server 9.0, and 8.5 is vulnerable to server-side request forgery (SSRF) with the Aja
CVE-2026-11708 CRITICAL 9.3 UPGRADE IBM WebSphere Application Server 9.0, and 8.5 is affected by a cross-site scripting vulnerability in the admin

References

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