What is CVE-2020-5253?

CVE-2020-5253 is a low-severity vulnerability in Nethack, classified under Incomplete List of Disallowed Inputs. CVSS score: 3.9/10. Published 2020-03-10.

How severe is CVE-2020-5253?

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

Privilege escalation in Nethack

CVE-2020-5253

NetHack before version 3.6.0 allowed malicious use of escaping of characters in the configuration file (usually .nethackrc) which could be exploited. This bug is patched in NetHack 3.6.0.

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: 0.005 (43.3th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 43rd percentile — 43.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000

Affected products

Nethack — versions < 3.6.0

Weakness classification (CWE)

References

github.com/NetHack/NetHack/security/advisories/GHSA-2c7p-3fj4-223m (Third Party Advisory)
github.com/NetHack/NetHack/commits/612755bfb5c412079795c68ba392df5d93874ed8 (Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2020-5253?: CVE-2020-5253 is a low-severity vulnerability in Nethack, classified under Incomplete List of Disallowed Inputs. CVSS score: 3.9/10. Published 2020-03-10.
How severe is CVE-2020-5253?: Low severity. CVSS v3 base score is 3.9 out of 10.