What is CVE-2019-18797?

CVE-2019-18797 is a medium-severity vulnerability in Sass-Lang Libsass, classified under Uncontrolled Recursion. CVSS score: 6.5/10. Published 2019-11-06.

How severe is CVE-2019-18797?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Vulnerability in Sass-Lang Libsass

CVE-2019-18797

LibSass 3.6.1 has uncontrolled recursion in Sass::Eval::operator()(Sass::Binary_Expression*) in eval.cpp.

Published 2019-11-06 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.015 (73.5th percentile), scored 2026-10-01.

Low probability of exploitation in the next 30 days, but still tracked. 73rd percentile — 73.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.015 · newest: 0.015 · change: 0.000

Affected products

Sass-Lang Libsass

Weakness classification (CWE)

CWE-674 — Uncontrolled Recursion

References

github.com/sass/libsass/issues/3000 (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2019-18797?: CVE-2019-18797 is a medium-severity vulnerability in Sass-Lang Libsass, classified under Uncontrolled Recursion. CVSS score: 6.5/10. Published 2019-11-06.
How severe is CVE-2019-18797?: Medium severity. CVSS v3 base score is 6.5 out of 10.