---
id: "CVE-2026-122096"
page: "https://infrastack.ai/live/CVE-2026-122096"
kind: "vulnerability"
aliases: ["CVE-2026-122096"]
title: "Apache DataSketches Java: crafted sketch input exhausts memory and hangs"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["apache-datasketches", "java", "package"]
not_affected_if: ["trusted-input-only"]
published_at: "2026-11-11T13:17:17+00:00"
first_seen_at: "2026-11-11T13:27:12+00:00"
updated_at: "2026-11-11T13:30:04+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-122096", "first_seen_at": "2026-11-11T13:27:12+00:00"}]
exploit_sources: []
---

# Apache DataSketches Java: crafted sketch input exhausts memory and hangs

Link for people: https://infrastack.ai/live/CVE-2026-122096 (this .md is for agents)

Several deserializers in Apache DataSketches Java trust sizes and counts in serialized input, so a small crafted input can force excessive memory allocation and an OutOfMemoryError. A crafted string passed to FrequentLongsSketch.getInstance(String) can also make deserialization or a later update loop indefinitely.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the DataSketches version in the project's build file, for example `datasketches-java` in pom.xml or build.gradle.
- Look for code that calls deserialization on sketches received from untrusted sources, including FrequentLongsSketch.getInstance(String).

## Fix

- Apache DataSketches Java: upgrade to `9.1.0`.

## Timeline

- 2026-11-11T13:27:12+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-122096

## Documents

- [fix] Release notes: github.com https://github.com/apache/datasketches-java/releases/tag/9.1.0

## From the sources

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.

---

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