A flaw in Node.js `crypto` causes the internal entropy caches used by `crypto.randomUUID()`, `crypto.randomUUIDv7()`, and `crypto.randomInt()` to be saved into user-land startup snapshots (`--build-snapshot`) and single executable applications built with `useSnapshot`. If any of these functions, or an API that relies on them such as `URL.createObjectURL()`, is called while the snapshot is built, every process started from that snapshot returns the same values until the cache is refilled: up to 127 UUIDs and about 1,000 `randomInt()` values. Identifiers expected to be unique can collide across processes, and values issued by one process can be predicted by observing another. This vulnerability affects Node.js 26.x, 24.x, and 22.x.

MediumVendor CVSS 4.8 / 10 1 CVE Published Oct 25, 2026 at 1:01 AM UTC

Summary

Mariner

Release Notes

Oct 25, 2026 at 1:01 AM UTC
Published by Microsoft Security Response Center
The publication date reported by the vendor.
Oct 26, 2026 at 2:50 PM UTC
Updated by Microsoft Security Response Center
The vendor changed the advisory after it was first published.
Oct 27, 2026 at 9:20 AM UTC
Added to SecurityAlert
We collected the advisory from the official source.
Oct 27, 2026 at 9:40 PM UTC
Confirmed at the source
Our collector saw this advisory during a later source check.

Details collected from Microsoft Security Response Center.

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