How severe is CVE-2018-16999?

CVE-2018-16999 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2018-16999 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (60th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-16999?

CVE-2018-16999 affects Nasm Netwide Assembler. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2018-16999?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2018-16999 published?

CVE-2018-16999 was published on 2018-09-13 and last updated on 2026-06-17.

CVE-2018-16999

CVE-2018-16999 is a medium-severity vulnerability in Nasm Netwide Assembler with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
CVSS v2: 4.3
EPSS exploit prediction: 1% (60th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Nasm Netwide Assembler
Published: 2018-09-13
Last modified: 2026-06-17

Description

Netwide Assembler (NASM) 2.14rc15 has an invalid memory write (segmentation fault) in expand_smacro in preproc.c, which allows attackers to cause a denial of service via a crafted input file.

Frequently asked questions

What is CVE-2018-16999?: Netwide Assembler (NASM) 2.14rc15 has an invalid memory write (segmentation fault) in expand_smacro in preproc.c, which allows attackers to cause a denial of service via a crafted input file.
How severe is CVE-2018-16999?: CVE-2018-16999 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2018-16999 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (60th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-16999?: CVE-2018-16999 affects Nasm Netwide Assembler. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2018-16999?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2018-16999 published?: CVE-2018-16999 was published on 2018-09-13 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:nasm:netwide_assembler:12.14:rc15:*:*:*:*:*:*

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