CVE-2026-106074 in Node.js
Summary
by MITRE • 10/23/2026
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**.
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Analysis
by VulDB Data Team • 10/23/2026
The identified flaw resides within the internal entropy management mechanisms of the Node.js crypto module, specifically affecting functions responsible for generating random values such as crypto.randomUUID(), crypto.randomUUIDv7(), and crypto.randomInt(). These functions rely on an internal cache to maintain high-quality entropy for efficient generation. The core technical failure occurs when this internal state is inadvertently serialized into user-land startup snapshots created via the --build-snapshot flag or single executable applications built with useSnapshot. This serialization process captures the current state of the entropy cache, including any buffered random values that have not yet been consumed by a running instance. Consequently, every new process initialized from such a snapshot inherits this static copy of the entropy pool rather than receiving fresh, unpredictable data derived from system-level sources like /dev/urandom or Windows BCryptGenRandom.
The operational impact of this vulnerability is severe due to the deterministic nature of the inherited state. When an application utilizing these crypto functions is launched from a vulnerable snapshot, it begins with the same sequence of random values that were present in the cache at the time the snapshot was built. This results in predictable outputs for up to 127 UUIDs and approximately one thousand calls to randomInt() before the internal cache refills itself with fresh entropy. In practical terms, this means that identifiers expected to be globally unique, such as session tokens, database keys, or security cookies generated via crypto.randomUUID(), will collide across different process instances if they are started from the same snapshot within a short timeframe. Furthermore, an attacker who can observe values issued by one process may predict subsequent values in another process derived from the same snapshot, effectively breaking the assumption of randomness required for secure cryptographic operations and session management.
This issue is particularly dangerous because it affects critical APIs that depend on underlying random number generation, including URL.createObjectURL(), which often relies on unique identifiers to manage object references securely. The vulnerability impacts Node.js versions 26.x, 24.x, and 22.x, representing a significant portion of the current long-term support and active development lines. From a classification perspective, this flaw aligns with CWE-330: Use of Insufficiently Random Values, as the system fails to generate values that are sufficiently unpredictable for their intended security context. It also relates to CWE-1257: Insecure Snapshotting or Serialization, where sensitive internal state is persisted in a way that compromises future instances. The attack vector corresponds to ATT&CK technique T1608: Link Input Files, as the vulnerability exploits the mechanism of linking application code and data into a single executable or snapshot file, allowing an adversary to leverage pre-computed states for prediction attacks rather than needing to break complex cryptographic algorithms directly.
Mitigation strategies must focus on preventing the serialization of sensitive entropy state during the build process. Developers should avoid using startup snapshots with --build-snapshot or useSnapshot in environments where crypto.randomUUID(), crypto.randomInt(), or dependent APIs are invoked prior to snapshot finalization, as this captures their internal cache state. If such functionality is required before snapshotting, it must be explicitly excluded from the snapshot scope by marking those modules or functions for exclusion during the build configuration. Alternatively, upgrading to a patched version of Node.js that corrects the serialization logic to exclude entropy caches is recommended. Until patches are applied, administrators should ensure that applications relying on high-entropy random values do not utilize startup snapshots unless they can guarantee that no crypto-related API calls occur before the snapshot is finalized and loaded by end users.