What is CVE-2020-5254?

CVE-2020-5254 is a low-severity vulnerability in Nethack, classified under Out-of-bounds Read. CVSS score: 3.9/10. Published 2020-03-10.

How severe is CVE-2020-5254?

Low severity. CVSS v3 base score is 3.9 out of 10.

Is CVE-2020-5254 known to be exploited?

7 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Out-of-bounds Read in Nethack

CVE-2020-5254

In NetHack before 3.6.6, some out-of-bound values for the hilite_status option can be exploited. NetHack 3.6.6 resolves this issue.

Vulnerability class: Buffer Overflow

Published 2020-03-10 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 3.9 (Low). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.011 (65.1th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 65th percentile — 65.1% 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 < 3.6.6

Weakness classification (CWE)

Public proof-of-concept exploits

References

github.com/NetHack/NetHack/security/advisories/GHSA-2ch6-6r8h-m2p9 (Vendor Advisory)

Frequently asked questions

What is CVE-2020-5254?: CVE-2020-5254 is a low-severity vulnerability in Nethack, classified under Out-of-bounds Read. CVSS score: 3.9/10. Published 2020-03-10.
How severe is CVE-2020-5254?: Low severity. CVSS v3 base score is 3.9 out of 10.
Is CVE-2020-5254 known to be exploited?: 7 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.