Security readout for executives and security teams
Plain-English summary
This critical vCenter flaw may let a network-connected attacker enter affected systems without valid credentials. Successful exploitation could expose or alter managed virtual infrastructure and disrupt operations. The supplied data does not identify exact vulnerable builds or a confirmed fix, so organisations should urgently reconcile deployments against Broadcom’s advisory.
Executive priority
Treat this as an immediate infrastructure-security priority. Identify every vCenter instance, establish network exposure, and obtain Broadcom’s exact build guidance. Prioritise reachable or business-critical management planes. Because the supplied affected-version data is ambiguous, do not infer safety from product family alone.
Technical view
CVE-2026-59309 is a CWE-303 authentication bypass in VMware Directory Service. It is remotely reachable, requires no privileges or user interaction, and has a CVSS 3.1 score of 9.8. A successful attacker may obtain unauthorised vCenter access, with potentially high confidentiality, integrity, and availability impact.
Likely exposure
Risk is greatest where vCenter management services are reachable from untrusted or broadly accessible networks. The bundle names several vCenter, Cloud Foundation, vSphere Foundation, and Telco Cloud version families, but also marks their default status unaffected. Exact affected builds therefore require vendor confirmation.
Exploitation context
The supplied record is not marked as CISA KEV and provides no evidence of active exploitation. It also does not establish public proof-of-concept availability. Nevertheless, network accessibility, no required credentials, low complexity, and potentially complete system impact make rapid defensive action appropriate.
Researcher notes
The record attributes the bypass to VMware Directory Service and supplies a CVSS vector of AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. It does not describe the vulnerable mechanism, affected endpoints, indicators, patches, or workarounds. The listed version families conflict with their default unaffected status, limiting precise exposure conclusions.
Mitigation direction
- Check Broadcom’s advisory immediately for affected builds, patches, upgrades, or vendor-approved workarounds.
- Restrict vCenter management access to approved administrative networks and trusted operators.
- Remove unnecessary internet or general-user network exposure to vCenter services.
- Apply vendor-directed remediation through established change-control and recovery procedures.
- Increase monitoring for unexpected authentication, privilege, and directory-service activity.
Validation and detection
- Inventory exact vCenter versions and builds, including instances bundled within named VMware platforms.
- Compare each build against Broadcom’s current affected-product and remediation information.
- Verify management interfaces are reachable only from explicitly approved network paths.
- Review logs for unexpected logins, privilege changes, and VMware Directory Service anomalies.
- After remediation, confirm installed builds and validate that unauthenticated access remains denied.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-303: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCredential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-59309 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9vmwareVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Incorrect Implementation of Authentication Algorithm
Incorrect Implementation of Authentication Algorithm represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.