---
id: "CVE-2026-128886"
page: "https://infrastack.ai/live/CVE-2026-128886"
kind: "vulnerability"
aliases: ["CVE-2026-128886"]
title: "dbus: stalled nonce-tcp connections block new clients, causing denial of service"
severity: "medium"
cvss: 6.2
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["dbus", "infrastructure", "linux", "self-hosted"]
not_affected_if: ["default-config", "local-socket-only"]
published_at: "2026-11-13T22:17:23+00:00"
first_seen_at: "2026-11-13T22:33:34+00:00"
updated_at: "2026-11-13T22:34:34+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-128886", "first_seen_at": "2026-11-13T22:33:34+00:00"}]
exploit_sources: []
---

# dbus: stalled nonce-tcp connections block new clients, causing denial of service

Link for people: https://infrastack.ai/live/CVE-2026-128886 (this .md is for agents)

When dbus runs with the nonce-tcp transport, a connection that never sends its authentication token is not timed out. Such a connection blocks the accept loop so legitimate clients cannot connect.

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

## How to check

- Check whether the dbus daemon is configured with the `nonce-tcp` transport in its dbus configuration files.
- Check the dbus version with `dbus-daemon --version`; the sources do not name affected or fixed versions.

## Timeline

- 2026-11-13T22:33:34+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-128886

## From the sources

A flaw was found in dbus when configured with the nonce-tcp transport. An unauthenticated attacker able to connect to an exposed listener can cause a Denial of Service (DoS) by opening a connection and withholding the expected authentication token. Because the server processes this verification without enforcing a timeout, the stalled connection blocks the accept process and prevents legitimate clients from establishing new connections.

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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_