---
id: "CVE-2026-123999"
page: "https://infrastack.ai/live/CVE-2026-123999"
kind: "vulnerability"
aliases: ["CVE-2026-123999"]
title: "ION-DTN: heap overflow in network manager daemon crashes telemetry collection"
severity: "high"
cvss: 8.7
epss: null
exploited: false
status: "open"
category: "runtime"
products: [{"name": "ION-DTN", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["ion-dtn", "nasa-jpl", "nm_mgr", "runtime", "space-networking"]
not_affected_if: ["nm_mgr-not-running", "version-outside-range"]
published_at: "2026-11-09T19:16:47+00:00"
first_seen_at: "2026-11-09T19:28:14+00:00"
updated_at: "2026-11-09T19:29:25+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-123999", "first_seen_at": "2026-11-09T19:28:14+00:00"}]
exploit_sources: []
---

# ION-DTN: heap overflow in network manager daemon crashes telemetry collection

Link for people: https://infrastack.ai/live/CVE-2026-123999 (this .md is for agents)

NASA JPL ION-DTN versions 3.6.2 through 4.2.0 have a heap buffer overflow in the nm_mgr network management daemon when it handles deeply nested AMP payloads. A malicious or misconfigured agent can send oversized AMP reports over UDP, crashing nm_mgr and halting telemetry and operator visibility.

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

## Affected

- vendor:ION-DTN affected range not listed fixed no fixed version listed

## How to check

- Check the installed ION-DTN version against the affected range `3.6.2` through `4.2.0`.
- Look for the `nm_mgr` daemon on hosts running ION-DTN and whether its UDP CLA/AMP path is reachable from other networks.

## Fix

- Move to a version newer than `4.2.0`; the fixed version is not stated in the sources provided.

## Timeline

- 2026-11-09T19:28:14+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-123999

## Documents

- [advisory] Vendor advisory: github.com https://github.com/nasa-jpl/ION-DTN/security/advisories/GHSA-gmhw-vmwr-wrxh
- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/ion-dtn-heap-buffer-overflow-via-nm-mgr-amp-rendering
- [fix] Release notes: github.com https://github.com/nasa-jpl/ION-DTN/releases/tag/ion-open-source-4.2.1-a.2

## From the sources

NASA JPL ION-DTN 3.6.2 through 4.2.0 contains a heap-based buffer overflow in the Network Management daemon (nm_mgr) string-formatting logic that allows a malicious or misconfigured agent to trigger an out-of-bounds write by sending deeply nested AMP payloads that exceed fixed-size buffer allocations through unbounded strcat operations. Attackers can transmit oversized AMP reports, tables, or macros over the UDP CLA/AMP path or trigger the flaw locally via interactive UI rendering to crash nm_mgr and cause a denial of service halting telemetry collection and operator visibility.

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