CVE-2025-9288

This vulnerability was marked as Important rather then Critical because while the lack of input type checks in sha.js allows for hash state rewinding, crafted collisions, and potential denial of service, the vulnerability requires highly specific crafted input objects that are unlikely to occur in typical real-world usage, especially since most applications pass well-formed strings or buffers to hashing functions. Moreover, the cryptographic breakages described, such as nonce reuse leading to private key extraction, are indirect and depend on downstream libraries misusing sha.js for sensitive operations without additional validation layers. As a result, the flaw significantly undermines correctness and robustness of the hashing API, but its exploitability in common production systems is constrained, which could justify viewing it as an Important vulnerability rather than a Critical one.

The flaw requires applications to pass attacker-controlled, non-standard JavaScript objects into hash.update(). Most real-world Node.js applications and libraries already use Buffer, TypedArray, or String inputs, which are unaffected. Furthermore, Node’s built-in crypto module, which is widely adopted, enforces stricter type-checking and is not impacted. As a result, the vulnerability mainly threatens projects that (a) directly depend on sha.js for cryptographically sensitive operations, and (b) hash untrusted input without type validation.