CVE-2017-12963: Libsass

High severity, CVSS 7.5. EPSS: 1.2% chance of exploitation in the next 30 days.

There is an illegal address access in Sass::Eval::operator() in eval.cpp of LibSass 3.4.5, leading to a remote denial of service attack. NOTE: this is similar to CVE-2017-11555 but remains exploitable after the vendor's CVE-2017-11555 fix (available from GitHub after 2017-07-24).

Affected products

• Libsass Libsass: version 3.4.5 only

Published 2017-08-18. Last modified 2026-06-17.