CVE-2026-33491Public exploit

Compiler crash or code execution via unchecked mangling

Published Mar 26, 2026 · Updated Mar 26, 2026

Stack-based buffer overflow in Zen C before 0.4.4 allows attackers to crash the compiler via crafted source-file identifiers. Name-mangling paths use sprintf and strcat to copy unbounded struct, trait, method, and generic names into fixed-size stack buffers. Processing an untrusted .zc file is required; a crash is demonstrated, while code execution is not demonstrated and would inherit the compiler process's privileges.

CVSS severity7.8
High
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in Zen C before 0.4.4 allows attackers to crash the compiler via crafted source-file identifiers. Name-mangling paths use sprintf and strcat to copy unbounded struct, trait, method, and generic names into fixed-size stack buffers. Processing an untrusted .zc file is required; a crash is demonstrated, while code execution is not demonstrated and would inherit the compiler process's privileges.

The record

CVE
CVE-2026-33491
Published
Mar 26, 2026
Updated
Mar 26, 2026
Vendor
Zen C
Product
Zen C
Classifications
CWE-121, CWE-787, T1203
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 26, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 0.4.4

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Zen C · Zen Cversion=< 0.4.4

Published CVSS scores

7.8GitHub, Inc.CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
CWE-787Out-of-bounds Write
T1203Exploitation for Client Execution

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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