What is CVE-2021-33452?

CVE-2021-33452 is a medium-severity vulnerability in Nasm Netwide Assembler, classified under Missing Release of Memory after Effective Lifetime. CVSS score: 5.5/10. Published 2022-07-26.

How severe is CVE-2021-33452?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Vulnerability in Nasm Netwide Assembler

CVE-2021-33452

An issue was discovered in NASM version 2.16rc0. There are memory leaks in nasm_malloc() in nasmlib/alloc.c.

Published 2022-07-26 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.003 (23.6th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 24th percentile — 23.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Nasm Netwide Assembler — versions 2.16

Weakness classification (CWE)

CWE-401 — Missing Release of Memory after Effective Lifetime

References

bugzilla.nasm.us/show_bug.cgi (Exploit, Third Party Advisory, Issue Tracking)
gist.github.com/Clingto/bb632c0c463f4b2c97e4f65f751c5e6d (Third Party Advisory)

Frequently asked questions

What is CVE-2021-33452?: CVE-2021-33452 is a medium-severity vulnerability in Nasm Netwide Assembler, classified under Missing Release of Memory after Effective Lifetime. CVSS score: 5.5/10. Published 2022-07-26.
How severe is CVE-2021-33452?: Medium severity. CVSS v3 base score is 5.5 out of 10.