How do I check whether I am affected by CVE-2026-124001?

- Find your ION-DTN version (source tree or package metadata); affected is 2.2.1b through 4.2.0, fixed in 4.2.1-a.2. - Check whether your ION configuration uses the DGR convergence layer. - Highest risk: DGR carried over internal IPC, custom transports, or synthetic datagrams. The advisory says standard UDP deployments were largely protected because network read limits cap datagram size. - Also check any custom code calling dgr_receive: the old API has no buffer capacity argument.

What is the fix for CVE-2026-124001?

Upgrade ION-DTN to 4.2.1-a.2 (ion-open-source-4.2.1-a.2). Fix checks contentLength against INT_MAX before allocation, adds a capacity parameter to dgr_receive, and updates AMS, BP and dgr2file callers.

Post Share

CRITICAL9.2CVSS · disclosure@vulncheck.com

NO KNOWN
EXPLOIT

ION-DTN · CVE-2026-124001 · Runtime

NASA ION-DTN: integer overflow in DGR layer lets crafted datagrams corrupt memory

Q: Who is not affected by CVE-2026-124001?

Not affected if: dgr-disabled, not-running-ion-dtn.

FIX → 4.2.1-a.2 ✓ verified

NASA JPL ION-DTN, a delay-tolerant networking suite, has an integer overflow in its Datagram Retransmission convergence layer. A crafted 64-bit svcDataLength value wraps a 32-bit allocation, so an unchecked memcpy in dgr_receive writes out of bounds, which can cause denial of service or possibly remote code execution.

Full story ↓Less ↑

first public Nov 7, 2026 · 2 sources

Could this affect your app?

Free first check from your website. Connect your repo for the full answer.

01 · Who is affected

✓ Verified Nov 9

Teams running NASA JPL ION-DTN 2.2.1b through 4.2.0 that use the DGR convergence layer. The advisory says standard UDP deployments were largely protected from remote exploitation by network read limits on datagram size; risk is higher where DGR runs over internal IPC or custom transports, or where synthetic datagrams bypass those limits. The advisory does not say whether DGR is on by default. Teams not running ION-DTN or not using DGR can skip it.

ION-DTN>= 2.2.1b, <= 4.2.0fixed in 4.2.1-a.2

Not affected if dgr-disabled, not-running-ion-dtn

Who cares dtn, ion-dtn, space-networking

02 · How to check

✓ Verified Nov 9

Find your ION-DTN version (source tree or package metadata); affected is 2.2.1b through 4.2.0, fixed in 4.2.1-a.2.
Check whether your ION configuration uses the DGR convergence layer.
Highest risk: DGR carried over internal IPC, custom transports, or synthetic datagrams. The advisory says standard UDP deployments were largely protected because network read limits cap datagram size.
Also check any custom code calling dgr_receive: the old API has no buffer capacity argument.

Exploited: No reports yet
Public exploit: None on GitHub
EPSS: Not scored
Last updated: Nov 9, 2026

How it unfolded

3 events · Nov 7, 2026 → Nov 9, 2026

Nov 7, 202600:28 UTCgithub.com Vendor advisory: github.com
Nov 9, 202619:28 UTCNVD CVE-2026-124001
Nov 9, 202619:30 UTCInfraStack Analyst GHSA-rcqq-5qmv-7fxp (vendor) read: affected 2.2.1b-4.2.0, patched 4.2.1-a.2; advisory says standard UDP deployments largely protected by read size limits; DGR default exposure not stated. Release page itself has no notes. Exa out of credits, no social search done.

What the sources say, verbatim

540 characters

NASA JPL ION-DTN 2.2.1b through 4.2.0 contains an integer overflow vulnerability in the Datagram Retransmission (DGR) convergence layer that allows attackers to corrupt heap memory by sending a maliciously crafted 64-bit svcDataLength value that wraps a 32-bit allocation size calculation. Attackers can exploit the dgr_receive API's unchecked memcpy operation using synthetic datagrams or DGR traffic over internal IPC or custom transports to trigger an out-of-bounds write, leading to denial of service or potential remote code execution.

Sources and references

NVD: CVE-2026-124001Nov 9, 2026
Release notes: github.comFix · github.com
Vendor advisory: github.comAdvisory · github.com
Third-party advisory: www.vulncheck.comAdvisory · vulncheck.com

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Post Share

CRITICAL9.2CVSS · disclosure@vulncheck.com

NO KNOWN
EXPLOIT

ION-DTN · CVE-2026-124001 · Runtime

NASA ION-DTN: integer overflow in DGR layer lets crafted datagrams corrupt memory

FIX → 4.2.1-a.2 ✓ verified

Full story ↓Less ↑

first public Nov 7, 2026 · 2 sources

Could this affect your app?

Free first check from your website. Connect your repo for the full answer.

01 · Who is affected

✓ Verified Nov 9

ION-DTN>= 2.2.1b, <= 4.2.0fixed in 4.2.1-a.2

Not affected if dgr-disabled, not-running-ion-dtn

Who cares dtn, ion-dtn, space-networking

02 · How to check

✓ Verified Nov 9

Find your ION-DTN version (source tree or package metadata); affected is 2.2.1b through 4.2.0, fixed in 4.2.1-a.2.
Check whether your ION configuration uses the DGR convergence layer.
Highest risk: DGR carried over internal IPC, custom transports, or synthetic datagrams. The advisory says standard UDP deployments were largely protected because network read limits cap datagram size.
Also check any custom code calling dgr_receive: the old API has no buffer capacity argument.

Exploited: No reports yet
Public exploit: None on GitHub
EPSS: Not scored
Last updated: Nov 9, 2026

How it unfolded

3 events · Nov 7, 2026 → Nov 9, 2026

Nov 7, 202600:28 UTCgithub.com Vendor advisory: github.com
Nov 9, 202619:28 UTCNVD CVE-2026-124001
Nov 9, 202619:30 UTCInfraStack Analyst GHSA-rcqq-5qmv-7fxp (vendor) read: affected 2.2.1b-4.2.0, patched 4.2.1-a.2; advisory says standard UDP deployments largely protected by read size limits; DGR default exposure not stated. Release page itself has no notes. Exa out of credits, no social search done.

What the sources say, verbatim

540 characters

Sources and references

NVD: CVE-2026-124001Nov 9, 2026
Release notes: github.comFix · github.com
Vendor advisory: github.comAdvisory · github.com
Third-party advisory: www.vulncheck.comAdvisory · vulncheck.com

This page as ·

Are you affected?

Tell InfraStack what you run. It checks this one, and every next one, against your stack.

Ask from here. InfraStack checks the affected versions against your stack and answers in your inbox.

InfraStack checks the affected versions against your stack and answers in Slack, with the evidence and the fix.

In Slack

Run the check

Get the next ION-DTN threat the day it hits your stack.

Start free

NASA ION-DTN: integer overflow in DGR layer lets crafted datagrams corrupt memory

01 · Who is affected

02 · How to check

How it unfolded

What the sources say, verbatim

Sources and references

Read next

Get the next ION-DTN threat the day it hits your stack.

NASA ION-DTN: integer overflow in DGR layer lets crafted datagrams corrupt memory

01 · Who is affected

02 · How to check

How it unfolded

What the sources say, verbatim

Sources and references

Read next

Get the next ION-DTN threat the day it hits your stack.

03 · The fix