CVE-2026-6068

Analyzed Analyzed - Analysis Complete

Heap Use-After-Free in NASM Response File Processing Causes Data Corruption

Publication date: 2026-04-10

Last updated on: 2026-05-26

Assigner: CERT/CC

Description

NASM contains a heap use after free vulnerability in response file (-@) processing where a dangling pointer to freed memory is stored in the global depend_file and later dereferenced, as the response-file buffer is freed before the pointer is used, allowing for data corruption or remote code execution.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-04-10

Last Modified

2026-05-26

Generated

2026-07-06

AI Q&A

2026-04-10

EPSS Evaluated

2026-07-05

NVD

CVE-2026-6068

EUVD

EUVD-2026-21380

Affected Vendors & Products

Vendor	Product	Version / Range
nasm	netwide_assembler	3.02

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-416	The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Attack-Flow Graph

Executive Summary

CVE-2026-6068 is a heap use-after-free vulnerability in NASM that occurs during the processing of response files specified with the -@ command-line option.

The vulnerability arises because a pointer to the response-file buffer is stored in a global variable called depend_file without copying the data. After the response-file buffer is freed, depend_file still points to this freed memory.

Later, when the program dereferences depend_file to compare filenames, it accesses memory that has already been freed, leading to a use-after-free condition. This can cause data corruption or unexpected behavior.

Compliance Impact

The provided information does not specify any direct impact of the NASM heap use after free vulnerability (CVE-2026-6068) on compliance with common standards and regulations such as GDPR or HIPAA.

Impact Analysis

This vulnerability can lead to data corruption or unexpected behavior in NASM when processing crafted response files.

Because it is a memory safety issue, it could potentially be exploited to cause crashes or to manipulate program execution, depending on the context in which NASM is used.

Detection Guidance

This vulnerability can be detected by running NASM with the response file option (-@) using crafted response files that trigger the heap use-after-free condition.

Using AddressSanitizer (ASan) to run NASM with response files is an effective way to detect the heap-use-after-free error, as ASan will report the memory error with a stack trace.

Compile NASM with AddressSanitizer enabled.
Run NASM with a crafted response file using the -@ option, for example: nasm -@ response_file
Monitor ASan output for heap-use-after-free errors referencing functions like process_respfile() and parse_cmdline().

Mitigation Strategies

To mitigate this vulnerability immediately, avoid using the response file option (-@) with NASM until a patched version is available.

If you must use response files, ensure they are from trusted sources and avoid any untrusted or crafted input that could exploit the heap use-after-free.

Monitor for updates or patches from the NASM project addressing this issue and apply them as soon as they are released.

Hi! I’m here to help you understand CVE-2026-6068. Ask me anything about the vulnerability, its impact, or mitigation strategies.

0/70