# CVE-2026-124001: NASA JPL ION-DTN integer overflow in DGR convergence layer

Source: https://junglewise.ai/threats/cve-2026-124001-nasa-jpl-ion-dtn-2-2-1b-through-4-2-0-contains-an-integer  
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-2026-124001 · Severity: high · CVSS 8.1 · Published 2026-11-09

NASA JPL ION-DTN is a delay-tolerant networking protocol implementation used in space and challenging communication environments. An integer overflow vulnerability in the Datagram Retransmission layer allows attackers to corrupt memory by sending malicious datagrams, potentially causing the system to crash or execute arbitrary code. Most standard UDP deployments have natural protection, but systems using internal IPC or custom transports are at higher risk.

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-2026-124001 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-124001 being exploited in the wild.

**How severe is CVE-2026-124001?** High severity, with a CVSS score of 8.1, published 9 November 2026.

**Which products and versions are affected?** NASA JPL ION-DTN 2.2.1b through 4.2.0.

**Is there a fix for CVE-2026-124001?** Yes: fixed in ION 4.2.1-a.2. Until then: Disable DGR convergence layer if not required. Restrict network access to ION-DTN instances and limit DGR traffic to trusted internal IPC channels only. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-124001 attacked?** It is attacked over the network or with local access, in a software library.

**Am I affected by CVE-2026-124001?** 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 ION 4.2.1-a.2

Disable DGR convergence layer if not required. Restrict network access to ION-DTN instances and limit DGR traffic to trusted internal IPC channels only.

## Technical details

The DGR convergence layer fails to validate a 64-bit svcDataLength field before converting it to a 32-bit allocation size, allowing integer wraparound that results in undersized heap buffers. The dgr_receive API then performs an unbounded memcpy into the allocated buffer without capacity checking, enabling out-of-bounds heap writes. Attackers can trigger this via synthetic datagrams on internal IPC or custom transports; standard UDP deployments are partially protected by implicit datagram size limits, but local exploitation is feasible.

## Affected products

- NASA JPL ION-DTN 2.2.1b through 4.2.0

## Timeline

- 2026-11-07: disclosed
- 2026-11-07: patched: ION 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-rcqq-5qmv-7fxp](https://github.com/nasa-jpl/ION-DTN/security/advisories/GHSA-rcqq-5qmv-7fxp)

## Related threats

- [NASA JPL ION-DTN heap buffer under-allocation in amsd](https://junglewise.ai/threats/cve-2026-124000-nasa-jpl-ion-dtn-2-1-0-through-4-2-0-contains-a-heap-buffer)
- [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)