What is CVE-2019-19777?

CVE-2019-19777 is a high-severity vulnerability in Nothings Stb Image.h, classified under Out-of-bounds Read. CVSS score: 8.8/10. Published 2019-12-13.

How severe is CVE-2019-19777?

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

Out-of-bounds Read in Nothings Stb Image.h

CVE-2019-19777

stb_image.h (aka the stb image loader) 2.23, as used in libsixel and other products, has a heap-based buffer over-read in stbi__load_main.

Vulnerability class: Buffer Overflow

Published 2019-12-13 · 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: 0.014 (71.9th percentile), scored 2026-10-20.

Low probability of exploitation in the next 30 days, but still tracked. 72nd percentile — 71.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.014 · newest: 0.014 · change: 0.000

Affected products

Nothings Stb Image.h — versions 2.23
Saitoha Libsixel — versions 1.8.2

Weakness classification (CWE)

CWE-125 — Out-of-bounds Read

References

github.com/saitoha/libsixel/issues/109 (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2019-19777?: CVE-2019-19777 is a high-severity vulnerability in Nothings Stb Image.h, classified under Out-of-bounds Read. CVSS score: 8.8/10. Published 2019-12-13.
How severe is CVE-2019-19777?: High severity. CVSS v3 base score is 8.8 out of 10.