How severe is CVE-2020-5209?

CVE-2020-5209 has a CVSS 3.x base score of 5.0, rated medium severity. It is exploitable over local access with high attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2020-5209 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-5209?

CVE-2020-5209 affects Nethack. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-5209?

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

When was CVE-2020-5209 published?

CVE-2020-5209 was published on 2020-01-28 and last updated on 2026-06-17.

CVE-2020-5209

CVE-2020-5209 is a medium-severity vulnerability in Nethack with a CVSS 3.x base score of 5.0. 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: Medium (CVSS 3.x base score 5.0)
CVSS v2: 4.6
EPSS exploit prediction: 1% (52nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-120
Affected product: Nethack
Published: 2020-01-28
Last modified: 2026-06-17

Description

In NetHack before 3.6.5, unknown options starting with -de and -i can cause a buffer overflow resulting in a crash or remote code execution/privilege escalation. This vulnerability affects systems that have NetHack installed suid/sgid and shared systems that allow users to influence command line options. Users should upgrade to NetHack 3.6.5.

Frequently asked questions

What is CVE-2020-5209?: In NetHack before 3.6.5, unknown options starting with -de and -i can cause a buffer overflow resulting in a crash or remote code execution/privilege escalation. This vulnerability affects systems that have NetHack installed suid/sgid and shared systems that allow users to influence command line options. Users should upgrade to NetHack 3.6.5.
How severe is CVE-2020-5209?: CVE-2020-5209 has a CVSS 3.x base score of 5.0, rated medium severity. It is exploitable over local access with high attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2020-5209 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-5209?: CVE-2020-5209 affects Nethack. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-5209?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-5209 published?: CVE-2020-5209 was published on 2020-01-28 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:nethack:nethack:*:*:*:*:*:*:*:*

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