How severe is CVE-2020-18974?

CVE-2020-18974 has a CVSS 3.x base score of 3.3, rated low 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 low.

Is CVE-2020-18974 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (53rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-18974?

CVE-2020-18974 affects Nasm Netwide Assembler. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-18974?

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

When was CVE-2020-18974 published?

CVE-2020-18974 was published on 2021-08-25 and last updated on 2026-06-17.

CVE-2020-18974

CVE-2020-18974 is a low-severity vulnerability in Nasm Netwide Assembler with a CVSS 3.x base score of 3.3. 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-120.

Key facts

Severity: Low (CVSS 3.x base score 3.3)
CVSS v2: 4.3
EPSS exploit prediction: 1% (53rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-120
Affected product: Nasm Netwide Assembler
Published: 2021-08-25
Last modified: 2026-06-17

Description

Buffer Overflow in Netwide Assembler (NASM) v2.15.xx allows attackers to cause a denial of service via 'crc64i' in the component 'nasmlib/crc64'. This issue is different than CVE-2019-7147.

Frequently asked questions

What is CVE-2020-18974?: Buffer Overflow in Netwide Assembler (NASM) v2.15.xx allows attackers to cause a denial of service via 'crc64i' in the component 'nasmlib/crc64'. This issue is different than CVE-2019-7147.
How severe is CVE-2020-18974?: CVE-2020-18974 has a CVSS 3.x base score of 3.3, rated low 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 low.
Is CVE-2020-18974 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (53rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-18974?: CVE-2020-18974 affects Nasm Netwide Assembler. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-18974?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-18974 published?: CVE-2020-18974 was published on 2021-08-25 and last updated on 2026-06-17.

References

https://bugzilla.nasm.us/show_bug.cgi?id=3392568

Affected products (1)

cpe:2.3:a:nasm:netwide_assembler:*:*:*:*:*:*:*:*

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