Encoding Error

Overview fast-uri is a Dependency-free RFC 3986 URI toolbox Affected versions of this package are vulnerable to Encoding Error in the mailto parser process. An attacker can inject unauthorized recipients or manipulate the subject and body fields by crafting a URI with percent-encoded reserved fie...

CVE-2026-86818

A flaw was found in fast-uri, a Node.js URI parser. In versions 4.1.3 and 4.1.4, the mailto parser incorrectly handles percent-encoded query field names. This desynchronization between parsing and serialization allows an attacker to inject arbitrary recipients, subjects, or body content into mail...

DEBIAN-CVE-2026-86818

fast-uri is a dependency-free RFC 3986 URI parser for Node.js, used by Fastify and ajv, that added a mailto scheme parser in version 4.1.3. In versions 4.1.3 and 4.1.4, the mailto parser compares each query field name to the reserved names to, subject, and body while the name is still...

CVE-2026-86818

fast-uri is a dependency-free RFC 3986 URI parser for Node.js, used by Fastify and ajv, that added a mailto scheme parser in version 4.1.3. In versions 4.1.3 and 4.1.4, the mailto parser compares each query field name to the reserved names to, subject, and body while the name is still...

CVE-2026-86818

fast-uri is a dependency-free RFC 3986 URI parser for Node.js, used by Fastify and ajv, that added a mailto scheme parser in version 4.1.3. In versions 4.1.3 and 4.1.4, the mailto parser compares each query field name to the reserved names to, subject, and body while the name is still...

Inappropriate Encoding for Output Context

Overview fast-uri is a Dependency-free RFC 3986 URI toolbox Affected versions of this package are vulnerable to Inappropriate Encoding for Output Context in the mailto parser when handling percent-encoded query field names. An attacker can manipulate email recipients, subjects, or body content by...

CVE-2026-86818

fast-uri v4.1.3–4.1.4, a dependency-free RFC 3986 URI parser for Node.js used by Fastify and ajv , suffers from a percent-encoded field-name desynchronization in its mailto parser. At parse time, reserved field names (to, subject, body) are compared in their still-percent-encoded form and thus no...

Linux Distros Unpatched Vulnerability : CVE-2026-86818

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - fast-uri is a dependency-free RFC 3986 URI parser for Node.js, used by Fastify and ajv, that added a mailto scheme parser in version 4.1.3. In versions 4.1.3 an...

PT-2026-91923

Name of the Vulnerable Software and Affected Versions fast-uri versions 4.1.3 through 4.1.4 Description The mailto parser compares query field names to reserved names such as to, subject, and body while they are still percent-encoded. Because the parser only decodes these names when storing them ...