# Deno v1.14.2 — Release & Upgrade Intelligence
- **Product:** Deno (https://deno.com)
- **Version:** v1.14.2
- **Released:** Sep 28, 2021
- **Impact Score:** 5/10
- **Breaking Changes:** Not verified
- **Canonical Analysis:** https://changelogs.us/deno/updates/v1.14.2/

## Executive Summary (TL;DR)
Deno v1.14.2. Source highlight: feat(cli/fmt): support more markdown extensions (#12195)

## New Features
- feat(cli/fmt): support more markdown extensions (#12195)

## Improvements
- perf(ext/fetch): Use the WebIDL conversion to DOMString rather than USVString
- perf(ext/fetch): skip USVString webidl conv on string constructor (#12168)
- perf(fetch): optimize InnerBody constructor (#12232)
- perf(fetch): optimize newInnerRequest blob url check (#12245)
- perf(fetch/Response): avoid class fields (#12237)
- perf(fetch/headers): optimize appendHeader (#12234)

## Bug Fixes
- fix(cli/permissions): ensure revoked permissions are no longer granted
- fix(ext/http): fortify "is websocket?" check (#12179)
- fix(ext/http): include port number in h2 urls (#12181)
- fix(ext/web): FileReader error messages (#12218)
- fix(ext/webidl): correctly apply [SymbolToStringTag] to interfaces (#11851)
- fix(http): panic when responding to a closed conn (#12216)