CVE-2026-9171: IBM WebSphere Application Server and WebSphere Application Server Liberty are vulnerable to a denial of servic

This month

HIGH 7.5REMOTEDOWNGRADE

CVE-2026-9171 is a high-severity flaw (CVSS 7.5) affecting powervm novalink. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

IBM WebSphere Application Server and WebSphere Application Server Liberty are vulnerable to a denial of service, caused by sending a specially-crafted request. A remote attacker could exploit this vulnerability to cause the server to consume memory resources.

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	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.5% (top 55%)
CISA exploited list	No
Weakness	CWE-400
Published	2026-07-17
Last modified	2026-10-24

Publisher (CNA): IBM Corporation · Vendor: ibm

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-17 19:17 UTCPublished CVE record published
2026-10-24 20:10 UTCUpdated Record last modified

ibm powervm novalink DOWNGRADE

Affected: 2.2.0 · 2.2.1 · 2.2.1.1 · 2.3.0 · 2.3.0.1 · 2.3.1 · 2.3.2

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.2.0

1. Check installed version

apt-cache policy powervm-novalink || rpm -q powervm-novalink || powervm-novalink --version

2. No fixed release: DOWNGRADE to a release before 2.2.0 (Debian / Ubuntu)

apt-cache madison powervm-novalink sudo apt install powervm-novalink=<VERSION_BEFORE_2.2.0> sudo apt-mark hold powervm-novalink

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

dnf --showduplicates list powervm-novalink sudo dnf downgrade powervm-novalink-<VERSION_BEFORE_2.2.0> sudo dnf versionlock add powervm-novalink

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-2026-9171?

powervm novalink: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-9171 being exploited?

CVE-2026-9171 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-2026-9171 affect?

CVE-2026-9171 affects powervm novalink. Severity is high (CVSS 7.5). IBM WebSphere Application Server and WebSphere Application Server Liberty are vulnerable to a denial of service, caused by sending a specially-crafted request. A remote attacker could exploit this vulnerability to cause the server to consum

How urgent is CVE-2026-9171?

Priority 43/100. High severity; Remotely exploitable, no login, no user action

Software pages

IBM WebSphere vulnerabilities

Related CVEs

CVE-2026-14971 LOW 3.9 DOWNGRADE IBM PowerVM Novalink 2.2.02.2.12.2.1.1, and 2.3.02.3.0.12.3.12.3.2 IBM NovaLink APIs misconfiguration may incr

References

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