What is CVE-2018-19755?

CVE-2018-19755 is a medium-severity vulnerability in Nasm Netwide Assembler, classified under Improper Input Validation. CVSS score: 5.5/10. Published 2018-11-30.

How severe is CVE-2018-19755?

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

Improper input validation in Nasm Netwide Assembler

CVE-2018-19755

There is an illegal address access at asm/preproc.c (function: is_mmacro) in Netwide Assembler (NASM) 2.14rc16 that will cause a denial of service (out-of-bounds array access) because a certain conversion can result in a negative integer.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

Published 2018-11-30 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.010 (61.3th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 61st percentile — 61.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.010 · newest: 0.010 · change: 0.000

Affected products

Nasm Netwide Assembler — versions 12.14

Weakness classification (CWE)

CWE-20 — Improper Input Validation

References

repo.or.cz/nasm.git/commit/3079f7966dbed4497e36d5067cbfd896a90358cb (Exploit, Third Party Advisory)
bugzilla.nasm.us/show_bug.cgi (Exploit, Third Party Advisory, Issue Tracking)

Frequently asked questions

What is CVE-2018-19755?: CVE-2018-19755 is a medium-severity vulnerability in Nasm Netwide Assembler, classified under Improper Input Validation. CVSS score: 5.5/10. Published 2018-11-30.
How severe is CVE-2018-19755?: Medium severity. CVSS v3 base score is 5.5 out of 10.