Improper handling of missing special element in .NET allows an unauthorized attacker to perform spoofing over a network.

The version of Tenable Identity Exposure running on the remote host is prior to 3.93.5. It is, therefore, affected by multiple vulnerabilities according to advisory TNS-2026-16:

  - Tenable Identity Exposure contains multiple unauthenticated API endpoints under /w/api/* that expose     sensitive application configuration data including cleartext LDAP credentials, SAML configuration, user     accounts, and directory settings to unauthenticated remote attackers. Affected responses are served with     Cache-Control: public headers and without Vary: Cookie, allowing reverse proxies and CDNs to cache and     serve sensitive data to unauthenticated users even after authentication is applied. (CVE-2026-13007)

  - Inconsistent interpretation of http requests ('http request/response smuggling') in ASP.NET Core allows     an authorized attacker to bypass a security feature over a network. (CVE-2025-55315)

  - Converting an excessively large OCTET STRING value to a hexadecimal string leads to a heap buffer     overflow on 32 bit platforms. A heap buffer overflow may lead to a crash or possibly an attacker     controlled code execution or other undefined behavior. (CVE-2026-31789)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of the Tenable Identity Exposure running on the remote host is prior to 3.77.17. It is, therefore, affected by multiple vulnerabilities according to advisory TNS-2026-11:

  - A flaw in Node.js's Permissions model allows attackers to bypass `--allow-fs-read` and `--allow-fs-write`     restrictions using crafted relative symlink paths. By chaining directories and symlinks, a script granted     access only to the current directory can escape the allowed path and read sensitive files. This breaks the     expected isolation guarantees and enables arbitrary file read/write, leading to potential system compromise.
    This vulnerability affects users of the permission model on Node.js v20, v22, v24, and v25. (CVE-2025-55130)

  - Improper access control in SQL Server allows an authorized attacker to elevate privileges over a network.
    (CVE-2026-21262)

  - Improper validation of specified type of input in SQL Server allows an authorized attacker to elevate     privileges over a network. (CVE-2026-26115)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of the Tenable Identity Exposure running on the remote host is prior to 3.77.17. It is, therefore, affected by multiple vulnerabilities according to advisory TNS-2026-11:

  - A flaw in Node.js's Permissions model allows attackers to bypass --allow-fs-read and --allow-fs-write     restrictions using crafted relative symlink paths. By chaining directories and symlinks, a script     granted access only to the current directory can escape the allowed path and read sensitive files. This     breaks the expected isolation guarantees and enables arbitrary file read/write, leading to potential     system compromise. (CVE-2025-55130)

  - Improper validation of specified type of input in SQL Server allows an authorized attacker to elevate     privileges over a network. (CVE-2026-26115)

  - Improper access control in Curl allows an authorized attacker to elevate privileges over a network.
    (CVE-2026-21262)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

An update of the dotnet package has been released.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - Improper handling of missing special element in .NET allows an unauthorized attacker to perform spoofing
    over a network. (CVE-2026-21218)

The remote Ubuntu 22.04 LTS / 25.10 host has packages installed that are affected by a vulnerability as referenced in the USN-8025-1 advisory.

    Kevin Jones discovered that the System.Security.Cryptography.Cose component in .NET did not properly     handle certain missing special elements in input data. An attacker could possibly use this issue to bypass     security checks and gain unauthorized access or perform data manipulation.

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - Improper handling of missing special element in .NET allows an unauthorized attacker to perform spoofing     over a network. (CVE-2026-21218)

Note that Nessus relies on the presence of the package as reported by the vendor.

The version of tested product installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the vendor advisory.

  - .NET Spoofing Vulnerability (CVE-2026-21218)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
322483	Tenable Identity Exposure < 3.93.5 Multiple Vulnerabilities (TNS-2026-16)	Nessus	Misc.	high
310403	Tenable Identity Exposure < 3.77.17 Multiple Vulnerabilities (TNS-2026-11)	Nessus	Misc.	high
307436	Tenable Identity Exposure < 3.77.17 Multiple Vulnerabilities (TNS-2026-11)	Nessus	Misc.	high
300527	Photon OS 5.0: Dotnet PHSA-2026-5.0-0778	Nessus	PhotonOS Local Security Checks	high
437930	Alpine: multiple aspnetcore9-runtime packages, multiple dotnet-host packages: security update to 9.0.13-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	high
437930	Alpine: multiple aspnetcore9-runtime packages, multiple dotnet-host packages: security update to 9.0.13-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	high
437929	Alpine: multiple aspnetcore8-runtime packages, multiple dotnet-host packages: security update to 8.0.24-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	high
437929	Alpine: multiple aspnetcore8-runtime packages, multiple dotnet-host packages: security update to 8.0.24-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	high
437914	Alpine: multiple aspnetcore10-runtime packages, multiple dotnet-host packages: security update to 10.0.3-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	high
437914	Alpine: multiple aspnetcore10-runtime packages, multiple dotnet-host packages: security update to 10.0.3-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	high
298898	Ubuntu 22.04 LTS / 25.10 : .NET vulnerability (USN-8025-1)	Nessus	Ubuntu Local Security Checks	high
298781	Linux Distros Unpatched Vulnerability : CVE-2026-21218	Nessus	Misc.	high
437684	SCA: security update for System.Security.Cryptography.Cose (GHSA-qvhc-9v3j-5rfw)	Tenable Cloud Security	SCA Checks	high
437684	SCA: security update for System.Security.Cryptography.Cose (GHSA-qvhc-9v3j-5rfw)	Tenable Self-Hosted Container Security	SCA Checks	high
298547	Security Update for Microsoft .NET Core (February 2026)	Nessus	Windows	high

Detections

Analytics

CVE-2026-21218

high

Tenable Plugins

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