What is CVE-2021-36531?

CVE-2021-36531 is a high-severity vulnerability in Miniupnp Project Ngiflib, classified under Out-of-bounds Write. CVSS score: 8.8/10. Published 2021-08-27.

How severe is CVE-2021-36531?

High severity. CVSS v3 base score is 8.8 out of 10.

Is CVE-2021-36531 known to be exploited?

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

Buffer overflow in Miniupnp Project Ngiflib

CVE-2021-36531

ngiflib 0.4 has a heap overflow in GetByte() at ngiflib.c:70 in NGIFLIB_NO_FILE mode, GetByte() reads memory buffer without checking the boundary.

Vulnerability class: Buffer Overflow

Published 2021-08-27 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.011 (63.3th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 63rd percentile — 63.3% 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

Miniupnp Project Ngiflib — versions 0.4

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

Public proof-of-concept exploits

References

github.com/miniupnp/ngiflib/issues/18 (Exploit, Patch, Third Party Advisory, Issue Tracking)

Frequently asked questions

What is CVE-2021-36531?: CVE-2021-36531 is a high-severity vulnerability in Miniupnp Project Ngiflib, classified under Out-of-bounds Write. CVSS score: 8.8/10. Published 2021-08-27.
How severe is CVE-2021-36531?: High severity. CVSS v3 base score is 8.8 out of 10.
Is CVE-2021-36531 known to be exploited?: 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.