CVE-2026-122096: Apache DataSketches Java: Uncontrolled resource consumption when deserializing crafted sketch images

Uncontrolled Resource Consumption vulnerability in the sketch deserialization of Apache DataSketches Java.

Several deserializers trusted sizes and counts declared in the serialized input. A small crafted input could make an application allocate an excessive amount of memory, leading to an OutOfMemoryError. A crafted string passed to FrequentLongsSketch.getInstance(String) could also make deserialization, or a later update, loop indefinitely. Only applications that deserialize sketches from untrusted sources are affected.

This issue affects Apache DataSketches Java: through 9.0.0.

Users are recommended to upgrade to version 9.1.0, which fixes the issue.