CVE-2026-6067Public exploit

Assembler crash via unchecked GROUP directive

Published Apr 10, 2026 · Updated Apr 10, 2026

Heap buffer overflow in NASM 3.02rc5 allows local users to corrupt heap memory and crash the assembler through a crafted assembly file. In output/outobj.c, obj_directive() processes a GROUP directive without checking bounds before writing to a heap buffer. A user or build process must assemble attacker-controlled source; the published proof of concept demonstrates the crash path, while code execution is not publicly demonstrated.

CVSS severity5.5
Medium
EPSS probability0.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap buffer overflow in NASM 3.02rc5 allows local users to corrupt heap memory and crash the assembler through a crafted assembly file. In output/outobj.c, obj_directive() processes a GROUP directive without checking bounds before writing to a heap buffer. A user or build process must assemble attacker-controlled source; the published proof of concept demonstrates the crash path, while code execution is not publicly demonstrated.

The record

CVE
CVE-2026-6067
Published
Apr 10, 2026
Updated
Apr 10, 2026
Vendor
NASM
Product
NASM
Classifications
CWE-787, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 10, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 10, 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=nasm-3.02rc5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

NASM · NASMversion=nasm-3.02rc5

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1204.002User Execution: Malicious File

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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