Preact, a lightweight web development framework, JSON serialization protection to prevent Virtual DOM elements from being constructed from arbitrary JSON. A regression introduced in Preact 10.26.5 caused this protection to be softened. In applications where values from JSON payloads are assumed to be strings and passed unmodified to Preact as children, a specially-crafted JSON payload could be constructed that would be incorrectly treated as a valid VNode. When this chain of failures occurs it can result in HTML injection, which can allow arbitrary script execution if not mitigated by CSP or other means. Applications using affected Preact versions are vulnerable if they meet all of the following conditions: first, pass unmodified, unsanitized values from user-modifiable data sources (APIs, databases, local storage, etc.) directly into the render tree; second assume these values are strings but the data source could return actual JavaScript objects instead of JSON strings; and third, the data source either fails to perform type sanitization AND blindly stores/returns raw objects interchangeably with strings, OR is compromised (e.g., poisoned local storage, filesystem, or database). Versions 10.26.10, 10.27.3, and 10.28.2 patch the issue. The patch versions restore the previous strict equality checks that prevent JSON-parsed objects from being treated as valid VNodes. Other mitigations are available for those who cannot immediately upgrade. Validate input types, cast or validate network data, sanitize external data, and use Content Security Policy (CSP).

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

  - Preact, a lightweight web development framework, JSON serialization protection to prevent Virtual DOM     elements from being constructed from arbitrary JSON. A regression introduced in Preact 10.26.5 caused this     protection to be softened. In applications where values from JSON payloads are assumed to be strings and     passed unmodified to Preact as children, a specially-crafted JSON payload could be constructed that would     be incorrectly treated as a valid VNode. When this chain of failures occurs it can result in HTML     injection, which can allow arbitrary script execution if not mitigated by CSP or other means. Applications     using affected Preact versions are vulnerable if they meet all of the following conditions: first, pass     unmodified, unsanitized values from user-modifiable data sources (APIs, databases, local storage, etc.)     directly into the render tree; second assume these values are strings but the data source could return     actual JavaScript objects instead of JSON strings; and third, the data source either fails to perform type     sanitization AND blindly stores/returns raw objects interchangeably with strings, OR is compromised (e.g.,     poisoned local storage, filesystem, or database). Versions 10.26.10, 10.27.3, and 10.28.2 patch the issue.
    The patch versions restore the previous strict equality checks that prevent JSON-parsed objects from being     treated as valid VNodes. Other mitigations are available for those who cannot immediately upgrade.
    Validate input types, cast or validate network data, sanitize external data, and use Content Security     Policy (CSP). (CVE-2026-22028)

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

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

  - Preact, a lightweight web development framework, JSON serialization protection to prevent Virtual DOM
    elements from being constructed from arbitrary JSON. A regression introduced in Preact 10.26.5 caused this
    protection to be softened. In applications where values from JSON payloads are assumed to be strings and
    passed unmodified to Preact as children, a specially-crafted JSON payload could be constructed that would
    be incorrectly treated as a valid VNode. When this chain of failures occurs it can result in HTML
    injection, which can allow arbitrary script execution if not mitigated by CSP or other means. Applications
    using affected Preact versions are vulnerable if they meet all of the following conditions: first, pass
    unmodified, unsanitized values from user-modifiable data sources (APIs, databases, local storage, etc.)
    directly into the render tree; second assume these values are strings but the data source could return
    actual JavaScript objects instead of JSON strings; and third, the data source either fails to perform type
    sanitization AND blindly stores/returns raw objects interchangeably with strings, OR is compromised (e.g.,
    poisoned local storage, filesystem, or database). Versions 10.26.10, 10.27.3, and 10.28.2 patch the issue.
    The patch versions restore the previous strict equality checks that prevent JSON-parsed objects from being
    treated as valid VNodes. Other mitigations are available for those who cannot immediately upgrade.
    Validate input types, cast or validate network data, sanitize external data, and use Content Security
    Policy (CSP). (CVE-2026-22028)

ID	Name	Product	Family	Type	Severity
282480	Linux Distros Unpatched Vulnerability : CVE-2026-22028	Nessus	Misc.	Local	critical
436603	SCA: security update for preact (GHSA-36hm-qxxp-pg3m)	Tenable Cloud Security	SCA Checks	Local	critical
436603	SCA: security update for preact (GHSA-36hm-qxxp-pg3m)	Tenable Self-Hosted Container Security	SCA Checks	Local	critical

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CVE-2026-22028

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critical