NASM’s disasm() function contains a stack based buffer overflow when formatting disassembly output, allowing an attacker triggered out-of-bounds write when slen exceeds the buffer capacity.

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

A heap buffer overflow vulnerability exists in the Netwide Assembler (NASM) due to a lack of bounds checking in the objdirective() function. This vulnerability can be exploited by a user assembling a malicious .asm file, potentially leading to heap memory corruption, denial of service (crash), and arbitrary code execution.

nasm v2.16 was discovered to contain a stack overflow in the Ndisasm component

Netwide Assembler (NASM) 2.13.02rc2 has a buffer over-read in the parseline function in asm/parser.c via uncontrolled access to nasmregflags.

Last updated 25 August 2025

Netwide Assembler (NASM) 2.13.02rc2 has a stack-based buffer under-read in the function ieeeshr in asm/float.c via a large shift value.

In Netwide Assembler (NASM) 2.14rc0, there is a use-after-free in ppverror in asm/preproc.c that will cause a remote denial of service attack.

In Netwide Assembler (NASM) 2.14rc0, there is an illegal address access in ismmacro() in asm/preproc.c that will cause a remote denial of service attack, because of a missing check for the relationship between minimum and maximum parameter counts.

In Netwide Assembler (NASM) 2.14rc0, there is a use-after-free in ppgetline in asm/preproc.c that will cause a remote denial of service attack.

In Netwide Assembler (NASM) 2.14rc0, there is a heap-based buffer over-read that will cause a remote denial of service attack, related to a while loop in pastetokens in asm/preproc.c.

In Netwide Assembler (NASM) 2.14rc0, there is an illegal address access in the function findcc() in asm/preproc.c that will cause a remote denial of service attack, because pointers associated with skipwhite calls are not validated.

In Netwide Assembler (NASM) 2.14rc0, there is a use-after-free in pplistonemacro in asm/preproc.c that will lead to a remote denial of service attack, related to mishandling of operand-type errors.

In Netwide Assembler (NASM) 2.14rc0, there is a use-after-free in the pplistonemacro function in asm/preproc.c that will cause a remote denial of service attack, related to mishandling of line-syntax errors.

In Netwide Assembler (NASM) 2.14rc0, there is a heap-based buffer over-read in the function detoken() in asm/preproc.c that will cause a remote denial of service attack.

In Netwide Assembler (NASM) 2.14rc0, there is a use-after-free in dodirective in asm/preproc.c that will cause a remote denial of service attack.

NASM v2.16 was discovered to contain a global buffer overflow in the component dbgdbgtypevalue at /output/outdbg.c.

NASM v2.16 was discovered to contain a segmentation violation in the component ieeewritefile at /output/outieee.c.

A vulnerability has been found in NASM Netwide Assember 2.17rc0. Affected is the function parseline of the file parser.c. The manipulation leads to stack-based buffer overflow. The attack needs to be approached locally. The exploit has been disclosed to the public and may be used.

A vulnerability has been found in NASM Netwide Assember 2.17rc0. Affected by this issue is the function dodirective of the file preproc.c. The manipulation leads to use after free. An attack has to be approached locally. The exploit has been disclosed to the public and may be used.

A vulnerability was found in NASM Netwide Assember 2.17rc0. This affects the function machonodeadstrip of the file outmacho.c. The manipulation leads to heap-based buffer overflow. Local access is required to approach this attack. The exploit has been disclosed to the public and may be used.

A vulnerability was determined in NASM Netwide Assember 2.17rc0. This vulnerability affects the function parsesmacrotemplate of the file preproc.c. The manipulation leads to null pointer dereference. Attacking locally is a requirement. The exploit has been disclosed to the public and may be used.

A vulnerability was identified in NASM Netwide Assember 2.17rc0. This issue affects the function assemblefile of the file nasm.c. The manipulation leads to stack-based buffer overflow. It is possible to launch the attack on the local host. The exploit has been disclosed to the public and may be used.

In Netwide Assembler (NASM) 2.15rc0, a heap-based buffer over-read occurs (via a crafted .asm file) in settextfree when called from expandonesmacro in asm/preproc.c.

In NASM 2.15.04rc3, there is a double-free vulnerability in pptokline asm/preproc.c. This is fixed in commit 8806c3ca007b84accac21dd88b900fb03614ceb7.

An infinite recursion issue was discovered in eval.c in Netwide Assembler (NASM) through 2.14.02. There is a stack exhaustion problem resulting from infinite recursion in the functions expr, rexp, bexpr and cexpr in certain scenarios involving lots of '{' characters. Remote attackers could leverage this vulnerability to cause a denial-of-service via a crafted asm file.

In Netwide Assembler (NASM) 2.14.02, stack consumption occurs in expr# functions in asm/eval.c. This potentially affects the relationships among expr0, expr1, expr2, expr3, expr4, expr5, and expr6 (and stdscan in asm/stdscan.c). This is similar to CVE-2019-6290 and CVE-2019-6291.

There is a use-after-free at asm/preproc.c (function ppgetline) in Netwide Assembler (NASM) 2.14rc16 that will cause a denial of service during certain finishes tests.

In Netwide Assembler (NASM) 2.15rc10, there is heap use-after-free in saawbytes in nasmlib/saa.c.

NASM 2.16 (development) is vulnerable to 476: Null Pointer Dereference via output/outaout.c.