Verified: Node v24.15.0 loads CJS modules through the ESM translator (when the module is served through a custom loader such as Yarn PnP's zip loader) with a require object that no longer has .extensions. Node v24.14.1 and earlier work correctly.

Real-world impact: next build on Next.js 15+ installed via Yarn PnP crashes in next/dist/build/next-config-ts/require-hook.js:35.

• hook.cjs / run.mjs — Variant A, plain filesystem. Does not reproduce.
• variant-b/ — Variant B, Yarn PnP. Reproduces.
• output-24.14.0.txt, output-24.15.0.txt — Variant A outputs (both succeed).
• output-variant-b-24.14.0.txt, output-variant-b-24.15.0.txt — Variant B outputs (one succeeds, one crashes).
• node-issue.md — draft bug report for nodejs/node.
• next-issue.md — draft bug report for vercel/next.js.

Requires two Node versions available locally. Adjust paths.

# Variant A (does NOT reproduce)
/path/to/node-24.14.0 run.mjs
/path/to/node-24.15.0 run.mjs

# Variant B (reproduces)
cd variant-b
/path/to/node-24.14.0 /path/to/yarn-4.14.1/yarn.js node run.mjs  # OK
/path/to/node-24.15.0 /path/to/yarn-4.14.1/yarn.js node run.mjs  # CRASH

• Plain await import('./hook.cjs') from a filesystem-relative path works on both Node versions. The regression only manifests when the CJS file's source URL comes through a custom loader (PnP serves them as file:///.../cache/*.zip/node_modules/*/index.cjs).
• In the failing case, typeof require is 'function' but typeof require.extensions is 'undefined', whereas on 24.14.1 (and in filesystem-loaded CJS generally) require.extensions is an object with .js, .json, and .node handlers.
• Stack trace top frames match what Next.js users see:

  loadCJSModule (node:internal/modules/esm/translators:185:3)
  ModuleWrap.<anonymous> (node:internal/modules/esm/translators:231:7)
  

• Likely introduced by nodejs/node#61769 ("lib: reduce cycles in esm loader and load it in snapshot"), which landed in Node 24.x for the first time in 24.15.0. Related: nodejs/node#62012 (EBADF fstat in the same subsystem, same version).