# CVE-2026-124000: NASA JPL ION-DTN heap buffer under-allocation in amsd

Source: https://junglewise.ai/threats/cve-2026-124000-nasa-jpl-ion-dtn-2-1-0-through-4-2-0-contains-a-heap-buffer  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-09. Updated: 2026-11-09  
License: CC BY 4.0 with a link back

CVE-2026-124000 · Severity: medium · CVSS 5.3 · Published 2026-11-09

NASA JPL ION-DTN is a delay-tolerant networking software suite used for space communications and remote network operations. A flaw in the Asynchronous Message Service daemon allows a rogue peer on the local network to send crafted configuration messages that crash the Configuration Server, causing a denial of service and potentially corrupting memory allocations within the daemon.

Technologies: [NASA JPL ION-DTN](https://junglewise.ai/threats/technologies/nasa-jpl-ion-dtn). Vendors: [NASA JPL](https://junglewise.ai/threats/vendors/nasa-jpl).

## Quick answers

**Is CVE-2026-124000 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-124000 being exploited in the wild.

**How severe is CVE-2026-124000?** Medium severity, with a CVSS score of 5.3, published 9 November 2026.

**Which products and versions are affected?** NASA JPL ION-DTN 2.1.0 through 4.2.0.

**Is there a fix for CVE-2026-124000?** Yes: fixed in 4.2.1-a.2. Until then: Restrict MAMS traffic to trusted internal peers and ensure AMS continua are properly isolated behind local host or perimeter firewalls; do not expose MAMS control-plane traffic to the public internet or across untrusted network boundaries. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-124000 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-124000?** Check whether you run NASA JPL ION-DTN at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 4.2.1-a.2

Restrict MAMS traffic to trusted internal peers and ensure AMS continua are properly isolated behind local host or perimeter firewalls; do not expose MAMS control-plane traffic to the public internet or across untrusted network boundaries.

## Technical details

The vulnerability is a heap buffer under-allocation in the AMS daemon's memory allocation logic for internal state-event objects during configuration message handling. An attacker on the local network with network access can send unauthenticated Meta-AMS (MAMS) configuration messages to trigger an out-of-bounds write, crashing the Configuration Server thread and destabilizing subsequent shared-memory allocations. The vulnerability affects versions 2.1.0 through 4.2.0 and requires no privileges or user interaction.

## Affected products

- NASA JPL ION-DTN 2.1.0 through 4.2.0

## Timeline

- 2026-11-07: disclosed
- 2026-11-07: patched: version 4.2.1-a.2 released

## References

- [https://github.com/nasa-jpl/ION-DTN/releases/tag/ion-open-source-4.2.1-a.2](https://github.com/nasa-jpl/ION-DTN/releases/tag/ion-open-source-4.2.1-a.2)
- [https://github.com/nasa-jpl/ION-DTN/security/advisories/GHSA-h28r-fr59-c79c](https://github.com/nasa-jpl/ION-DTN/security/advisories/GHSA-h28r-fr59-c79c)

## Related threats

- [NASA JPL ION-DTN integer overflow in DGR convergence layer](https://junglewise.ai/threats/cve-2026-124001-nasa-jpl-ion-dtn-2-2-1b-through-4-2-0-contains-an-integer)
- [NASA JPL ION-DTN heap-based buffer overflow in nm_mgr](https://junglewise.ai/threats/cve-2026-123999-nasa-jpl-ion-dtn-3-6-2-through-4-2-0-contains-a-heap-based)