Security Resilience

CVE-2026-84731

Auth Bypass

Published
15 October 2026
Modified
15 October 2026
CVSS Score v4 9.3
Click a component to see what it means
Raw vectorCVSS: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:Red
EPSS Score 0.013 70th percentile
Risk Priority 48 floored blend · peak EPSS

CVSS 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

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,…

more

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

T1001.001 Junk Data Command And Control
Adversaries may add junk data to protocols used for command and control to make detection more difficult.
T1001.002 Steganography Command And Control
Adversaries may use steganographic techniques to hide command and control traffic to make detection efforts more difficult.
T1003.002 Security Account Manager Credential Access
Adversaries may attempt to extract credential material from the Security Account Manager (SAM) database either through in-memory techniques or through the Windows Registry where the SAM database is stored.
T1003.003 NTDS Credential Access
Adversaries may attempt to access or create a copy of the Active Directory domain database in order to steal credential information, as well as obtain other information about domain members such as devices, users, and access rights.
T1003.005 Cached Domain Credentials Credential Access
Adversaries may attempt to access cached domain credentials used to allow authentication to occur in the event a domain controller is unavailable.
T1003.007 Proc Filesystem Credential Access
Adversaries may gather credentials from the proc filesystem or `/proc`.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

Affected Assets

Nutanix
Prism Element
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 9 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V6.4.3
  • V10.4.16
  • V11.4.3
  • V7.2.4

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.

addresses: CWE-306 CWE-290

Requires authentication of devices prior to connection, preventing exploitation of missing authentication for critical network functions.

addresses: CWE-306 CWE-290

Mandates authentication prior to establishing communications with services, preventing missing authentication for this critical function.

addresses: CWE-306

Requires established identification and authentication to unlock, mitigating missing authentication for continued system access.

addresses: CWE-306

Requiring identification and rationale for actions allowed without authentication ensures critical functions are not left unprotected by forcing review of authentication requirements.

addresses: CWE-306

Authorizing mobile device connections to organizational systems ensures authentication is performed for this critical access function.

addresses: CWE-306

Guarantees critical functions are protected by mandatory invocation of the access control mechanism.

addresses: CWE-290

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.

PR.AA-01 partial match
blocks

Managing identities and credentials is a prerequisite for authentication but does not itself enforce it on critical functions.

PR.AA-02 partial match
blocks

Proofing and binding identities reduces spoofing opportunities during enrollment but does not address runtime authentication implementation flaws.

PR.AA-03 partial match
blocks

Requiring authentication of users/services/hardware directly counters spoofing-based bypass when strong methods are used.

PR.AA-04 partial match
blocks

Protecting, conveying, and verifying identity assertions specifically prevents the spoofing that enables authentication bypass.

PR.AA-05 partial match
blocks

Least-privilege authorization policies reduce impact of bypassed authentication but do not address the root flaw.

PR.IR-01 partial match
blocks

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.

removes
blocks

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.

blocks

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.

blocks

Authentication information management directly addresses credential handling that prevents spoofing.

blocks

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.

removes

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

References