typescript-eslint 8.71.0: no-unsafe-enum-assignment + rule fixes (28 Sep 2026)

On 28 September 2026, typescript-eslint published v8.71.0, a minor release that adds a new type-aware rule and several plugin fixes. ShopperCove did not upgrade a production lint pipeline for this note and did not run benchmarks. Package identity was confirmed on the npm registry on 5 October 2026 (@typescript-eslint/eslint-plugin@8.71.0, dist-tag latest). Primary sources: the GitHub release v8.71.0 and the rule docs for no-unsafe-enum-assignment. This is a docs-based upgrade checklist—not performance advice and not a security advisory (no CVEs are claimed here).

There is no affiliate link in this article. This post has no affiliate links.

New rule: @typescript-eslint/no-unsafe-enum-assignment

Extending plugin:@typescript-eslint/strict-type-checked enables this rule. It requires type information (with the usual type-checked lint performance tradeoffs).

What it targets: TypeScript is deliberately lenient about assigning plain number values into numeric enums (useful for bit-flag combinations). The cost is that any number—including one that matches no enum member—can land in an enum-typed location. Numeric literals that merely coincide with a member’s value, and arithmetic that yields a plain number, have the same problem.

The rule reports those unsafe assignments so you depend on named members, not accidental numeric coincidence.

From the official examples:

Options: none (not configurable).

When not to use it (per docs): codebases that intentionally derive enum values with non-bitwise operators; validating untrusted API/user input before treating it as an enum (temporary disables or a validator like Zod may be better); third-party enums imported only as types; or teams that treat enums as a namespaced bag of values (consider const object + union instead).

Enable explicitly if you are not on strict-type-checked:

// eslint.config.mjs (flat)
rules: {
  "@typescript-eslint/no-unsafe-enum-assignment": "error",
}

Fixes in 8.71.0

From the release notes:

Hands-on upgrade checklist

1. Inventory: npm ls @typescript-eslint/eslint-plugin (and matching @typescript-eslint/parser / utils). Note whether you are below 8.71.0.
2. Pin / bump in staging: install @typescript-eslint/eslint-plugin@8.71.0 (and keep sister packages on the same 8.71.0 line). Confirm with npm view @typescript-eslint/eslint-plugin version → expect 8.71.0 as latest as of sources read 5 Oct 2026.
3. Type-aware config: if you use strict-type-checked, expect no-unsafe-enum-assignment to light up on numeric-enum assignment patterns. If you only use recommended (non-strict) configs, decide whether to enable the rule deliberately.
4. Re-run lint CI: watch for new enum-assignment findings and for quieter/more accurate results on the four fixed rules above.
5. Do not invent security urgency: this minor is features + bugfixes in the official release notes; ShopperCove is not attaching CVE IDs.

ShopperCove did not change production typescript-eslint versions for this article. Prefer the GitHub release and rule docs over third-party roundups. For core ESLint (not this plugin), see the live ShopperCove note on ESLint v10.12.0.

Bottom line

typescript-eslint v8.71.0 (28 Sep 2026) adds no-unsafe-enum-assignment for type-aware configs and ships four useful rule fixes. Pin @typescript-eslint/*@8.71.0 when ready. No affiliate.

Sources

• https://github.com/typescript-eslint/typescript-eslint/releases/tag/v8.71.0
• https://typescript-eslint.io/rules/no-unsafe-enum-assignment/
• https://www.npmjs.com/package/@typescript-eslint/eslint-plugin
• https://registry.npmjs.org/@typescript-eslint/eslint-plugin/8.71.0
• https://typescript-eslint.io/users/releases/

Related

• https://www.shoppercove.com/blog/eslint-10-12-release-october-2026
• https://www.shoppercove.com/blog/vite-plus-1-0-unified-toolchain-october-2026
• https://www.shoppercove.com/blog/playwright-1-63-test-locks-october-2026
• https://www.shoppercove.com/blog/astro-7-3-preview-ignore-lock-october-2026
• https://www.shoppercove.com/blog/angular-router-ssr-queryparams-dos-october-2026
• https://www.shoppercove.com/blog/webpack-5-111-esm-output-stable-september-2026
• https://www.shoppercove.com/blog/nodejs-26-lts-october-2026-schedule-change
• https://www.shoppercove.com/blog/nextjs-15-lts-end-of-support-october-2026