CVE-2026-59347: VMware Workstation and Fusion HGFS stack-based buffer-overflow vulnerability

Recommended actionWithin 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available

What, why and how

VMware Workstation and Fusion contain a stack-based buffer-overflow vulnerability in HGFS. A malicious actor with local administrative privileges on a virtual machine may exploit this issue to execute code as the virtual machine's VMX process running on the host. Affected versions: - VMware Workstation: 25H2, 26H1 (fixed in 26H1u1) - VMware Fusion: 25H2, 26H1 (fixed in 26H1u1)

What

Why

A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).

How

An attacker operating through local access may attempt exploitation without authentication or user interaction. If successful, the issue may execute code or commands in the affected security context.

What

Why

A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).

How

An attacker operating through local access may attempt exploitation without authentication or user interaction. If successful, the issue may execute code or commands in the affected security context.

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation

Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.

No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material

Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.

None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path: local access → Stack-based Buffer Overflow → execute code or commands in the affected security context
Attack surface: Local
Privileges required: None: unauthenticated exploitation is possible
User interaction: None
Attack complexity: High: exploitation depends on specific conditions
Security boundary: Changed: exploitation can affect a different security authority
Weakness ? CWE means Common Weakness Enumeration: a standard category for the underlying weakness.: CWE-121 ↗
CWE-121: Stack-based Buffer Overflow. A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).
CVSS vector ? CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SChangedScope: The attack can affect a component governed by a different security authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land: After compromise, an attacker may use built-in shells, scripting engines, scheduled tasks and native network utilities for discovery, persistence or movement. This is a plausible LoTL path, not evidence that it has occurred for every attack.

UnauthenticatedRemote code executionCWE-121

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2026-94169Official EUVD mapping

Official EUVD record ↗

BSI · German · WID-SEC-2026-3169VMware Fusion und Workstation: Mehrere Schwachstellen ermöglichen Codeausführung

Ein lokaler Angreifer kann mehrere Schwachstellen in VMware Workstation und VMware Fusion ausnutzen, um beliebigen Programmcode auszuführen.

Official advisory ↗

Canadian Centre for Cyber Security · English · AV26-1008Broadcom VMware security advisory (AV26-1008)

As of October 7, 2026, VMware is affected by vulnerabilities in the following products:

Official advisory ↗

Cyber Security Agency of Singapore · English · CSA-SB-20261021Security Bulletin 21 Oct 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 21 Oct 2026, published on 21 October 2026. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗

Cyber Security Agency of Singapore · English · CSA-SB-20261014Security Bulletin 14 Oct 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 14 Oct 2026, published on 14 October 2026. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗

INCIBE-CERT · Spanish · multiples-vulnerabilidades-en-productos-de-vmware-6Múltiples vulnerabilidades en productos de VMware

h4urek, Y², Stan S, Yeonghyeon Choi y Tianchu Chen han informado sobre 2 vulnerabilidades: una de severidad crítica y otra de severidad alta que, en caso de ser explotadas, podrían permitir a un atacante con privilegios de administrador en una máquina virtual ejecutar código en el sistema anfitrión.

Official advisory ↗

Patch and workaround

Operational remediation based on structured source evidence.

Status ? Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.: Patch available
Affected: VMware Fusion: 25H2 ≤ 26H1
VMware Workstation: 25H2 ≤ 26H1
Fixed: VMware Workstation: 26H1u1
VMware Fusion: 26H1u1
Action: Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround: No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.

Evidence and provenance

Published 7 Oct 2026 · Last source change 7 Oct 2026, 11:29 UTC · CWE-121 · Stack-based Buffer Overflow

CVE recordCVE.org · 5.2

CVSS sourceCNA

EPSS source

The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.

FIRST · tracked since 2026-10-07

European sourceENISA EUVD · EUVD-2026-94169

Product sourceCNA

Remediation sourceCVE/CNA references

CWE sourceCNA

NVD statusNVD awaiting enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗

13 Oct 2026, 08:12 UTC
BlackTree coverageBlackTree article coverage changed from no BlackTree article to 1 BlackTree article.
Before
no BlackTree article
After
1 BlackTree article
BlackTree editorial ↗
7 Oct 2026, 23:14 UTC
ENISA EUVD mappingEUVD-2026-94169 was added to the official ENISA EUVD mapping for this CVE.
Before
not recorded
After
{"euvdId":"EUVD-2026-94169"}
ENISA EUVD ↗
7 Oct 2026, 05:40 UTC
Vendor guidanceAuthoritative vendor guidance changed: removed vendor advisory: support.broadcom.com/38288.
Before
remediation: support.broadcom.com/38288 · vendor advisory: support.broadcom.com/38288
After
remediation: support.broadcom.com/38288
CNA ↗
7 Oct 2026, 05:40 UTC
Affected versionsThe structured affected or fixed version information changed.
Before
See the linked VMware advisory for the product-specific affected versions. · Fixed: No verified fixed release is recorded in this advisory.
After
VMware Workstation: 25H2 ≤ 26H1; VMware Fusion: 25H2 ≤ 26H1 · Fixed: VMware Workstation: 26H1u1; VMware Fusion: 26H1u1
CNA ↗
7 Oct 2026, 05:40 UTC
Remediation statusRemediation status changed from Awaiting fix to Patch available.
Before
Awaiting fix
After
Patch available
CNA ↗
7 Oct 2026, 05:40 UTC
SeveritySeverity changed from Critical to High.
Before
Critical
After
High
CNA ↗
7 Oct 2026, 05:40 UTC
CVSS scoreCVSS score changed from not recorded to 8.1 (CVSS 3.1 · CNA · CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H).
Before
not recorded
After
8.1 (CVSS 3.1 · CNA · CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H)
CNA ↗
3 Sep 2026, 08:58 UTC
Catalogue recordCVE added to the BlackTree catalogue.
Authoritative vendor security advisory ↗

2026-10-07CVE published

2026-10-07Fixed release or patch reference recorded

ENISA EUVD · EUVD-2026-94169↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗

Technical terms and abbreviations used in this report

CVE: Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS: Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS: Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE: Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA: CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP: Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD: National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT: A computer security incident response team that publishes warnings or coordinates incident response.
PoC: Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF: Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL: Living off the land: abuse of legitimate tools or system functions during an attack.

VMware Workstation and Fusion HGFS stack-based buffer-overflow vulnerability

Published severity in operational context

Evidence used

Compensating controls

Verification

National CERT insights
?
CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

ENISA European Vulnerability Database

EUVD-2026-94169

What, why and how

Exploit reality and attack path

Official authority intelligence

Patch and workaround

Evidence and provenance

What changed after publication