CVE-2026-84731
Raw vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:N/AU:Y/R:U/V:C/RE:H/U:RedCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-84731 is a critical-severity Authentication Bypass by Spoofing (CWE-290) vulnerability in Nutanix Prism Element (inferred from references). Its CVSS base score is 9.3 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Junk Data (T1001.001); ranked in the top 30% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-102206
Vulnerability Data
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,…
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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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
Affected Assets
Mitigating Controls
Control response
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- 9 hardening rules · 3 OS baselines
V6.4.3V10.4.16V11.4.3V7.2.4
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Requires authentication for non-organizational users, preventing access to critical functions without proper identification and authentication.
Requires authentication of devices prior to connection, preventing exploitation of missing authentication for critical network functions.
Mandates authentication prior to establishing communications with services, preventing missing authentication for this critical function.
Requires established identification and authentication to unlock, mitigating missing authentication for continued system access.
Requiring identification and rationale for actions allowed without authentication ensures critical functions are not left unprotected by forcing review of authentication requirements.
Authorizing mobile device connections to organizational systems ensures authentication is performed for this critical access function.
Guarantees critical functions are protected by mandatory invocation of the access control mechanism.
Reveals spoofed logon attempts through unexpected previous logon timestamps upon legitimate login.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Managing identities and credentials is a prerequisite for authentication but does not itself enforce it on critical functions.
Proofing and binding identities reduces spoofing opportunities during enrollment but does not address runtime authentication implementation flaws.
Requiring authentication of users/services/hardware directly counters spoofing-based bypass when strong methods are used.
Protecting, conveying, and verifying identity assertions specifically prevents the spoofing that enables authentication bypass.
Least-privilege authorization policies reduce impact of bypassed authentication but do not address the root flaw.
Protecting networks from unauthorized access can be undermined by missing authentication but does not address the root authentication gap.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
A.5.15 only requires that an access control policy and requirements be defined and communicated; it does not itself implement, enforce or configure any authentication scheme that would stop spoofing attacks from bypassing authentication, so the weakness remains fully exploitable.
A.5.16 manages the lifecycle, uniqueness, and accountability of identities; it does not implement or strengthen authentication schemes against spoofing, so the CWE-290 exploit remains possible even when identities are correctly provisioned and tracked.
Authentication information management directly addresses credential handling that prevents spoofing.
A.5.18 governs the provisioning, review, and revocation of already-granted access rights to authenticated identities; it has no bearing on whether an authentication scheme can be spoofed or bypassed before any rights are assigned.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (higher-evidence rows only; rows rated `none` are excluded).
Oracle Linux 8 (2 rules)
- V-248827 OL 8 must not have the rsh-server package installed. blocks CWE-290, CWE-306
- V-248585 OL 8 must require reauthentication when using the "sudo" command. blocks CWE-306
RHEL 7 (2 rules)
- V-204442 The Red Hat Enterprise Linux operating system must not have the rsh-server package installed. blocks CWE-290, CWE-306
- V-237635 The Red Hat Enterprise Linux operating system must require re-authentication when using the "sudo" command. blocks CWE-306
RHEL 8 (2 rules)
- V-230492 RHEL 8 must not have the rsh-server package installed. blocks CWE-290, CWE-306
- V-237643 RHEL 8 must require re-authentication when using the "sudo" command. blocks CWE-306