What’s Vulnerable › Vulnerabilities

CVE-2020-5211: NetHack AUTOCOMPLETE configuration file option is subject to a buffer overflow

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-01-28 · updated 2026-06-17
• Weakness: CWE-120

Description

In NetHack before 3.6.5, an invalid extended command in value for the AUTOCOMPLETE configuration file option 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 upload their own configuration files. Users should upgrade to NetHack 3.6.5.

Affected products

• NetHack: before 3.6.5 — fixed in 3.6.5

How to fix

Upgrade to a fixed version: NetHack 3.6.5. Check the vendor advisory for mitigations.

References

• https://github.com/NetHack/NetHack/security/advisories/GHSA-r788-4jf4-r9f7
• https://github.com/NetHack/NetHack/security/advisories/GHSA-r788-4jf4-r9f7

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