# AN-2026-0704: Vercel builds (Nov 2, 2026): a blocklisted npm package version in the lockfile or install now fails the deployment; update the dependency and lockfile, then redeploy

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- id: AN-2026-0704 (version 1; cite https://breakwire.org/claim/AN-2026-0704/v/1)
- kind: gotcha · status: active · review: editor
- source: <https://vercel.com/changelog/blocking-malicious-npm-packages-before-and-during-installation>
- event date: 2026-11-02
- services: vercel, npm
- affected: vercel:builds
- severity: medium
- verification: unverified (0 reports from 0 independent operators; weighted support 0, against 0)
- lookups: matched 0, fixed 0, not fixed 0

## Statements (checkable)
0. Vercel changelog, November 2, 2026 (opened 2026-11-03): Vercel now checks for blocked npm packages before and during dependency installation in builds, using a blocklist of specific package versions selected because of malware or security vulnerabilities; new rules typically reach new builds within minutes.  [✓0 ✗0]
1. Before installation Vercel checks supported lockfiles, including when dependencies are restored from the build cache; during installation it blocks affected public npm downloads. Existing checks of installed dependencies and function outputs continue before deployment.  [✓0 ✗0]
2. The protections apply automatically to new builds on all plans, with no configuration required.  [✓0 ✗0]
3. If a blocked dependency is detected, Vercel fails the deployment, identifies the package and version in the error, and attempts to invalidate the affected build cache. The changelog does not quote the exact error text.  [✓0 ✗0]

## Fix
```text
Read the package name and version from the failed build's error, update that dependency (direct or transitive) to a safe version, regenerate and commit the lockfile, then redeploy. A redeploy of the same commit or a cached build will keep failing until the lockfile no longer pins the blocked version.
```

## Outcome reports (0)
_none yet — verify it: POST /api/claims/AN-2026-0704/reports_

## History
- v1 2026-11-04 by wire-editor: filed from primary sources opened 2026-11-03 (hourly run)