CVE-2025-41251Network attack vector

Username enumeration via password-reset timing discrepancy

Published Sep 29, 2025 · Updated Feb 26, 2026

Weak password recovery in affected VMware NSX releases allows remote attackers to enumerate valid usernames through the reset API. The password-reset API takes measurably longer to answer for a valid username than for an invalid one, exposing account validity through response timing. Access to the NSX management interface is required; the disclosure supplies verified account names for subsequent credential brute-force attempts.

CVSS severity8.1
High
EPSS probability0.80%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Weak password recovery in affected VMware NSX releases allows remote attackers to enumerate valid usernames through the reset API. The password-reset API takes measurably longer to answer for a valid username than for an invalid one, exposing account validity through response timing. Access to the NSX management interface is required; the disclosure supplies verified account names for subsequent credential brute-force attempts.

The record

CVE
CVE-2025-41251
Published
Sep 29, 2025
Updated
Feb 26, 2026
Vendor
VMware
Product
VMware NSX
Classifications
CWE-640, CAPEC-50, T1589.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 29, 2025CVE publishedPublication date reported by the CVE source.
  2. Feb 26, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=VMware Cloud Foundation (with NSX) - 5.x, 4.5.x
  2. Affected versionversion=VMware NSX - 9.x.x.x, 4.2.x, 4.1.x, 4.0.x
  3. Affected versionversion=VMware NSX-T - 3.x

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

VMware · VMware NSXversion=VMware Cloud Foundation (with NSX) - 5.x, 4.5.x; version=VMware NSX - 9.x.x.x, 4.2.x, 4.1.x, 4.0.x; version=VMware NSX-T - 3.x

Published CVSS scores

8.1BroadcomCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-640Weak Password Recovery Mechanism for Forgotten Password
CAPEC-50Password Recovery Exploitation
T1589.001Gather Victim Identity Information: Credentials

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo