fast-uri before 4.1.2, 3.1.5, and 2.4.4 requires a literal double forward slash to recognize a URI authority, so a reference that uses a backslash based introducer in place of it (backslash backslash, forward slash backslash, or backslash forward slash) is parsed with no authority and folds into the path. Node's native WHATWG URL parser instead treats a backslash as interchangeable with a forward slash for special schemes, so the two parsers extract different hosts from the same input. Applications that use fast-uri to enforce host based policy such as allowlists, SSRF filtering, or redirect validation before passing the same URL into Node's URL or fetch consumers can be steered to an unintended host. Upgrade to fast-uri 4.1.2, 3.1.5, or 2.4.4.

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

  - fast-uri before 4.1.2, 3.1.5, and 2.4.4 requires a literal double forward slash to recognize a URI
    authority, so a reference that uses a backslash based introducer in place of it (backslash backslash,
    forward slash backslash, or backslash forward slash) is parsed with no authority and folds into the path.
    Node's native WHATWG URL parser instead treats a backslash as interchangeable with a forward slash for
    special schemes, so the two parsers extract different hosts from the same input. Applications that use
    fast-uri to enforce host based policy such as allowlists, SSRF filtering, or redirect validation before
    passing the same URL into Node's URL or fetch consumers can be steered to an unintended host. Upgrade to
    fast-uri 4.1.2, 3.1.5, or 2.4.4. (CVE-2026-18446)

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

  - fast-uri before 4.1.2, 3.1.5, and 2.4.4 requires a literal double forward slash to recognize a URI     authority, so a reference that uses a backslash based introducer in place of it (backslash backslash,     forward slash backslash, or backslash forward slash) is parsed with no authority and folds into the path.
    Node's native WHATWG URL parser instead treats a backslash as interchangeable with a forward slash for     special schemes, so the two parsers extract different hosts from the same input. Applications that use     fast-uri to enforce host based policy such as allowlists, SSRF filtering, or redirect validation before     passing the same URL into Node's URL or fetch consumers can be steered to an unintended host. Upgrade to     fast-uri 4.1.2, 3.1.5, or 2.4.4. (CVE-2026-18446)

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

ID	Name	Product	Family	Type	Severity
445608	SCA: security update for fast-uri (GHSA-7p8r-x3mc-p8w7)	Tenable Cloud Security	SCA Checks	Local	high
445608	SCA: security update for fast-uri (GHSA-7p8r-x3mc-p8w7)	Tenable Self-Hosted Container Security	SCA Checks	Local	high
331478	Linux Distros Unpatched Vulnerability : CVE-2026-18446	Nessus	Misc.	Local	high

Detections

Analytics

CVE-2026-18446

high

Tenable Plugins

high

high

high