What is CVE-2020-5212?

CVE-2020-5212 is a medium-severity vulnerability in Nethack, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 5.0/10. Published 2020-01-28.

How severe is CVE-2020-5212?

Medium severity. CVSS v3 base score is 5.0 out of 10.

Buffer overflow in Nethack

CVE-2020-5212

In NetHack before 3.6.5, an extremely long value for the MENUCOLOR 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.

Vulnerability class: Buffer Overflow

Published 2020-01-28 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.0 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.011 (63.4th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 63rd percentile — 63.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.011 · newest: 0.011 · change: 0.000

Affected products

Nethack — versions < 3.6.5

Weakness classification (CWE)

CWE-120 — Buffer Copy without Checking Size of Input (Classic Buffer Overflow)

References

github.com/NetHack/NetHack/security/advisories/GHSA-g89f-m829-4m56 (Third Party Advisory)

Frequently asked questions

What is CVE-2020-5212?: CVE-2020-5212 is a medium-severity vulnerability in Nethack, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 5.0/10. Published 2020-01-28.
How severe is CVE-2020-5212?: Medium severity. CVSS v3 base score is 5.0 out of 10.