Acropolis Operating System (AOS): Authentication Bypass by Spoofing
CVE-2026-84731 is a critical-severity authentication bypass by spoofing vulnerability in Acropolis Operating System (AOS) from Nutanix, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 7.3.1.18, 7.5.2, 7.6.0.8 as the first without the flaw, so updating Acropolis Operating System (AOS) to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.28% chance of exploitation within 30 days, higher than 71% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Acropolis Operating System (AOS) to 7.3.1.18 or 7.5.2 or 7.6.0.8, whichever matches your release line, or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Nutanix | Acropolis Operating System (AOS) | before 7.3.1.18; 7.5 up to, but not including, 7.5.2; 7.6 up to, but not including, 7.6.0.8 | 7.3.1.18, 7.5.2, 7.6.0.8 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 9.3 | Critical | CNA |
| CVSS 3.1 | 9.8 | Critical | CNA |
| CVSS 2.0 | 10.0 | High | CNA |
Official description
An unauthenticated remote attacker can bypass authentication and gain full access to administrative API endpoints in Nutanix Prism Element by including a crafted internal management HTTP header. The vulnerability is caused by a misconfiguration in the application's authentication filters. Consequently, the server responds with a Set-Cookie header containing a valid JSESSIONID. This session cookie decodes to a JSON Web Token (JWT) granting maximum cluster administrative privileges. Successful exploitation allows the attacker to execute root-level commands on all Controller VMs (CVMs) in the cluster, leading to complete cluster destruction and unauthorized access to VM memory and virtual disks.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Authentication Bypass by Spoofing
This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.
More Authentication Bypass by Spoofing vulnerabilities (CWE-290)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Recent Authentication Bypass by Spoofing vulnerabilities
- 9.8 Critical severity
- 9.1 Critical severity
- 7.5 High severity
- 8.1 High severity
- 7.5 High severity
- 9.3 Critical severity
Spotted an error? Tell us.