---
id: "CVE-2026-122020"
kind: "vulnerability"
aliases: ["CVE-2026-122020"]
title: "Nstbrowser: stopAll endpoint flaw lets remote users cause denial of service"
severity: "medium"
cvss: 5.0
epss: null
exploited: false
status: "open"
category: "other"
products: []
ecosystems: []
tags: ["browser-automation", "nstbrowser", "other"]
not_affected_if: ["unknown"]
published_at: "2026-11-04T22:17:56+00:00"
first_seen_at: "2026-11-04T23:08:48+00:00"
updated_at: "2026-11-04T23:10:08+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-122020", "first_seen_at": "2026-11-04T23:08:48+00:00"}]
exploit_sources: []
---

# Nstbrowser: stopAll endpoint flaw lets remote users cause denial of service

Nstbrowser up to 1.2.1 has a flaw in the stopAllBrowsers function behind the /api/agent/browser/stopAll endpoint of its Local Agent Management Service. A remote attacker can manipulate it to cause a denial of service, and a public exploit has been released.

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

## How to check

- Check whether Nstbrowser is installed and its version is `1.2.1` or lower
- Check whether the Local Agent Management Service is reachable from the network: unknown

## Timeline

- 2026-11-04T23:08:48+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-122020

## From the sources

A security flaw has been discovered in NST Labs Tech Nstbrowser up to 1.2.1. The affected element is the function stopAllBrowsers of the file /api/agent/browser/stopAll of the component Local Agent Management Service. Performing a manipulation results in denial of service. Remote exploitation of the attack is possible. The exploit has been released to the public and may be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_