---
id: "CVE-2026-63540"
page: "https://infrastack.ai/live/CVE-2026-63540"
kind: "vulnerability"
aliases: ["CVE-2026-63540"]
title: "Hyperscan: heap buffer overflow lets a local user crash the system"
severity: "medium"
cvss: 6.9
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["c", "hyperscan", "package", "regex"]
not_affected_if: ["hyperscan-not-installed", "version-at-or-above-5.4.2.1"]
published_at: "2026-11-10T18:17:45+00:00"
first_seen_at: "2026-11-10T18:23:01+00:00"
updated_at: "2026-11-10T18:24:34+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-63540", "first_seen_at": "2026-11-10T18:23:01+00:00"}]
exploit_sources: []
---

# Hyperscan: heap buffer overflow lets a local user crash the system

Link for people: https://infrastack.ai/live/CVE-2026-63540 (this .md is for agents)

Hyperscan, Intel's regular-expression matching library, has a heap-based buffer overflow before version v5.4.2.1 that an unprivileged local user can trigger. An attacker can cause a denial of service, and the description also notes possible integrity impact.

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

## How to check

- Check the installed Hyperscan version against `v5.4.2.1`

## Fix

- Hyperscan: move to `v5.4.2.1` or later

## Timeline

- 2026-11-10T18:23:01+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-63540

## From the sources

Heap-based buffer overflow for some Hyperscan before version v5.4.2.1 within Ring 3: User Applications may allow a denial of service. Unprivileged software adversary with an unauthenticated user combined with a low complexity attack may enable denial of service. This result may potentially occur via local access when attack requirements are not present without special internal knowledge and requires passive user interaction. The potential vulnerability may impact the confidentiality (none), integrity (low) and availability (high) of the vulnerable system, resulting in subsequent system confidentiality (none), integrity (none) and availability (none) impacts.

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_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_