CVE-2026-59309: VMware vCenter contains an authentication bypass vulnerability in the VMware Directory Service. A malicious ac

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CRITICAL 9.8REMOTEUPGRADE

CVE-2026-59309 is a critical-severity flaw (CVSS 9.8) affecting vcenter server. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

VMware vCenter contains an authentication bypass vulnerability in the VMware Directory Service. A malicious actor with network access to vCenter may exploit this issue to bypass authentication and gain unauthorized access to the system.

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 51%)
CISA exploited list	No
Weakness	CWE-303
Published	2026-07-30
Last modified	2026-08-25

Publisher (CNA): VMware · Vendor: vmware

Last updated 2026-08-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-30 13:16 UTCPublished CVE record published
2026-08-25 18:12 UTCUpdated Record last modified

vmware vcenter server UPGRADE

Affected: < 8.0 · 8.0 · 8.0 a · 8.0 b · 8.0 c · 8.0 update1 · 8.0 update1a · 8.0 update1b

Fixed in: 8.0, 9.0.2.0100, 9.1.0.0300

Safe to downgrade to: a release before 8.0

1. Check installed version

apt-cache policy vcenter-server || rpm -q vcenter-server || vcenter-server --version

2. UPGRADE to 8.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade vcenter-server

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade vcenter-server

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 8.0 (Debian / Ubuntu)

apt-cache madison vcenter-server sudo apt install vcenter-server=<VERSION_BEFORE_8.0> sudo apt-mark hold vcenter-server

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list vcenter-server sudo dnf downgrade vcenter-server-<VERSION_BEFORE_8.0> sudo dnf versionlock add vcenter-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.

Advisories and coverage

Official advisories

Google Cloud Security Bulletins: GCP-2026-050 2026-10-26

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-2026-59309?

vcenter server: upgrade to 8.0, 9.0.2.0100, 9.1.0.0300. Exact commands for each OS are on this page.

Is CVE-2026-59309 being exploited?

CVE-2026-59309 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-2026-59309 affect?

CVE-2026-59309 affects vcenter server. Severity is critical (CVSS 9.8). VMware vCenter contains an authentication bypass vulnerability in the VMware Directory Service. A malicious actor with network access to vCenter may exploit this issue to bypass authentication and gain unauthorized access to the system.

How urgent is CVE-2026-59309?

Priority 52/100. Critical severity; Remotely exploitable, no login, no user action

Software pages

VMware vulnerabilities

Related CVEs

CVE-2026-59310 CRITICAL 9.8 EXPLOITED UPGRADE Broadcom VMware vCenter Path Traversal Vulnerability

References

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