CVE-2021-45256
A Null Pointer Dereference vulnerability existfs in nasm 2.16rc0 via asm/preproc.c.
A Null Pointer Dereference vulnerability existfs in nasm 2.16rc0 via asm/preproc.c.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
A Null Pointer Dereference vulnerability existfs in nasm 2.16rc0 via asm/preproc.c.
- Record
CVE-2021-45256- CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H - CVSS 2.0
- 4.3 Medium
AV:N/AC:M/Au:N/C:N/I:N/A:P - Weakness
- CWE-476
- Updated
- 2026-11-02
CVE List No score
A Null Pointer Dereference vulnerability existfs in nasm 2.16rc0 via asm/preproc.c.
- Record
CVE-2021-45256- Updated
- 2026-11-02
EUVDEUVD-2021-32036 No score
A Null Pointer Dereference vulnerability existfs in nasm 2.16rc0 via asm/preproc.c.
- Record
EUVD-2021-32036- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-vc9p-94q9-qg8c No score
A Null Pointer Dereference vulnerability existfs in nasm 2.16rc0 via asm/preproc.c.
A Null Pointer Dereference vulnerability existfs in nasm 2.16rc0 via asm/preproc.c.
- Record
GHSA-vc9p-94q9-qg8c- Weakness
- CWE-476
- Updated
- 2026-11-02
OSV
A Null Pointer Dereference vulnerability existfs in nasm 2.16rc0 via asm/preproc.c.
- Record
CVE-2021-45256- CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVDEBIAN-CVE-2021-45256
A Null Pointer Dereference vulnerability existfs in nasm 2.16rc0 via asm/preproc.c.
- Record
DEBIAN-CVE-2021-45256- CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2021-45256
A Null Pointer Dereference vulnerability existfs in nasm 2.16rc0 via asm/preproc.c.
- Record
UBUNTU-CVE-2021-45256- CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
nasmDebian:12 |
All versions, plus listed versions 2.16.01-12.16.03-13.01-1 |
None known |
nasmDebian:13 |
All versions, plus listed versions 2.16.03-13.01-1 |
None known |
nasmDebian:14 |
All versions, plus listed versions 2.16.03-13.01-1 |
None known |
nasmUbuntu:16.04:LTS |
All versions, plus listed versions 2.11.06-1really2.11.05-12.11.08-12.11.08-1ubuntu0.1 |
None known |
nasmUbuntu:18.04:LTS |
All versions, plus listed versions 2.13.01-22.13.02-0.1 |
None known |
nasmUbuntu:20.04:LTS |
All versions, plus listed versions 2.14.02-1 |
None known |
nasmUbuntu:Pro:22.04:LTS |
All versions, plus listed versions 2.15.05-12.15.05-1ubuntu0.1~esm12.15.05-1ubuntu0.1~esm2 |
None known |
nasmUbuntu:Pro:24.04:LTS |
All versions, plus listed versions 2.16.01-12.16.01-1build12.16.01-1ubuntu0.1~esm12.16.01-1ubuntu0.1~esm2 |
None known |
nasmUbuntu:25.10 |
All versions, plus listed versions 2.16.03-1 |
None known |
nasmUbuntu:26.10 |
All versions, plus listed versions 3.01-1 |
None known |
nasmUbuntu:26.04:LTS |
All versions, plus listed versions 2.16.03-13.01-1 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-45256 is a medium vulnerability (CVSS 5.5) in Nasm Netwide Assembler, published December 22, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.69%, the 53rd percentile. No source names a fixed version.