Inappropriate Encoding for Output Context Affecting dotnet package, versions *


Severity

Recommended
0.0
medium
0
10

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
0.25% (15th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-RHEL8-DOTNET-19990010
  • published20 Sept 2026
  • disclosed15 Sept 2026

Introduced: 15 Sep 2026

NewCVE-2026-86818  (opens in a new tab)
CWE-838  (opens in a new tab)

How to fix?

There is no fixed version for RHEL:8 dotnet.

NVD Description

Note: Versions mentioned in the description apply only to the upstream dotnet package and not the dotnet package as distributed by RHEL. See How to fix? for RHEL:8 relevant fixed versions and status.

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 percent-encoded, and decodes it only when storing it as a generic header, so a percent-encoded spelling of a reserved field name is not recognized as that field at parse time but is re-emitted as the literal field name when the parsed URI is serialized. An application that validates, logs, or displays the recipient list from the first parse and then serializes the URI and sends it can silently gain an attacker-chosen recipient, and the subject and body fields can be smuggled across the same roundtrip. The issue is fixed in fast-uri 4.1.5, and users should upgrade to 4.1.5 or later. As a workaround, do not act on a mailto URI that fast-uri has re-serialized without first decoding and re-validating its recipient, subject, and body fields.

CVSS Base Scores

version 3.1