Username Enumeration in VMware NSX
CVE-2025-41252 is a remote, unauthenticated username enumeration vulnerability in VMware NSX. The issue affects the authentication logic of NSX management interfaces, including web and API login endpoints, where observable differences in responses for valid versus invalid usernames can disclose whether an account exists. Reported discrepancies may include differing error messages, HTTP status codes, or timing behavior. An attacker can automate authentication attempts against exposed NSX interfaces to identify valid usernames without prior access. Affected products include VMware NSX 9.x.x.x, 4.2.x, 4.1.x, 4.0.x, NSX-T 3.x, and VMware Cloud Foundation deployments that include NSX, including 5.x and 4.5.x.
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Impact, mitigation & remediation
What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.
Impact
What an attacker gets, and what they’ve been doing with it.
Mitigation
If you can’t patch tonight, do this now.
Remediation
Patch, then assume compromise.
Exploits
No public exploits tracked yet. Mallory keeps watching.
No public exploit code observed for this vulnerability.
Affected products & vendors
Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.
Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.
Recent activity
16 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
A high-severity vulnerability in VMware NSX (details not provided in the content) for which Broadcom released patches.
A critical vulnerability in Broadcom VMware, details not specified in the content.
A high-severity unauthenticated username enumeration vulnerability in VMware NSX/NSX-T that supports account discovery and can be chained with credential attacks and other flaws to progress from unauthenticated recon to authenticated compromise.
A high-severity VMware NSX username enumeration vulnerability that allows unauthenticated attackers to enumerate valid usernames.
The version that knows your environment.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.