CVE-2021-45256

Name: CVE-2021-45256
Creator: NVD / NIST
Published: 2021-12-22T17:15:09.17+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.5/10EPSS 0.61%

Last modified Jun 17, 2026

CVE-2021-45256 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. A Null Pointer Dereference vulnerability existfs in nasm 2.16rc0 via asm/preproc.c.. EPSS estimates a 0.61% chance of exploitation in the next 30 days.

Description

A Null Pointer Dereference vulnerability existfs in nasm 2.16rc0 via asm/preproc.c.

Metrics

CVSS 3.1

5.5/10

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

EPSS Probability

0.61%

44.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-476

Affected Software

Vendor	Product	Versions	Update
Nasm	Netwide Assembler	2.16	Rc0

References

https://bugzilla.nasm.us/show_bug.cgi?id=3392789Broken Link, Issue Tracking
https://bugzilla.nasm.us/show_bug.cgi?id=3392789Broken Link, Issue Tracking

Timeline

Published: Dec 22, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-45256?

A Null Pointer Dereference vulnerability existfs in nasm 2.16rc0 via asm/preproc.c.

How severe is CVE-2021-45256?

CVE-2021-45256 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.61% probability of exploitation in the next 30 days.

How do I fix CVE-2021-45256?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-45256?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST